feat(go): port socket detectors

This commit is contained in:
Luna 2026-07-10 17:29:07 -07:00
parent fc9b5f0448
commit c6f7219de8
23 changed files with 693 additions and 28 deletions

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@ -32,9 +32,10 @@ bcc/eBPF telemetry.
An experimental, non-installing Phase 1 Go sidecar now lives under `go-agent/`. An experimental, non-installing Phase 1 Go sidecar now lives under `go-agent/`.
It is stdlib-only, emits `enodia.event.v1` JSONL, captures an injectable process It is stdlib-only, emits `enodia.event.v1` JSONL, captures an injectable process
and file-descriptor view, and currently ports `ld_preload`, `deleted_exe`, file-descriptor, and socket view, and currently ports `reverse_shell`,
`input_snooper`, and `credential_access`. Python remains the production agent `ld_preload`, `deleted_exe`, `input_snooper`, `credential_access`,
and parity oracle; do not describe the Go path as a replacement yet. `stealth_network`, and `egress`. Python remains the production agent and parity
oracle; do not describe the Go path as a replacement yet.
Implemented detection coverage: Implemented detection coverage:

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@ -66,10 +66,11 @@ Project docs:
Phase 1 now also has an **experimental Go sidecar** under `go-agent/`. It emits Phase 1 now also has an **experimental Go sidecar** under `go-agent/`. It emits
the same `enodia.event.v1` envelope and captures an injectable `/proc` process the same `enodia.event.v1` envelope and captures an injectable `/proc` process
view. The first parity-checked cohort is `ld_preload`, `deleted_exe`, and `ss` socket view. The parity-checked cohort is `reverse_shell`,
`input_snooper`, and `credential_access`. It is stdout-only and does not `ld_preload`, `deleted_exe`, `input_snooper`, `credential_access`,
replace, install over, or write state for the Python daemon; Python remains `stealth_network`, and `egress`. It is stdout-only and does not replace,
authoritative until subsystem parity is complete. install over, or write state for the Python daemon; Python remains authoritative
until subsystem parity is complete.
## Why these detectors ## Why these detectors

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@ -260,10 +260,11 @@ Exit criteria:
- Suricata model assimilation design is complete, and Phase 0's additive - Suricata model assimilation design is complete, and Phase 0's additive
`enodia.event.v1` Python reference contract is implemented. `enodia.event.v1` Python reference contract is implemented.
- Phase 1 is in progress under `go-agent/`: a stdlib-only parallel sweep loop, - Phase 1 is in progress under `go-agent/`: a stdlib-only parallel sweep loop,
injectable process/file-descriptor state, and the first poll-detector cohort injectable process/file-descriptor/socket state, and seven poll detectors
(`ld_preload`, `deleted_exe`, `input_snooper`, `credential_access`) are (`reverse_shell`, `ld_preload`, `deleted_exe`, `input_snooper`,
checked against the Python oracle with a shared fixture. The Go sidecar `credential_access`, `stealth_network`, `egress`) are checked against the
remains stdout-only and non-production until broader parity lands. Python oracle with a shared fixture. The Go sidecar remains stdout-only and
non-production until broader parity lands.
## Backlog ## Backlog

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@ -228,8 +228,9 @@ signature keeps `sid` / `signature` / `classtype` / tests / docs.
equivalent, poll detectors ported, JSON output matching schemas. Runs equivalent, poll detectors ported, JSON output matching schemas. Runs
alongside Python; harness compares both. *In progress:* the isolated alongside Python; harness compares both. *In progress:* the isolated
`go-agent/` sidecar now has stdlib config loading, an injectable `/proc` `go-agent/` sidecar now has stdlib config loading, an injectable `/proc`
process/file-descriptor view, the JSONL sweep loop, and fixture parity for process/file-descriptor and `ss` socket view, the JSONL sweep loop, and
`ld_preload`, `deleted_exe`, `input_snooper`, and `credential_access`; fixture parity for `reverse_shell`, `ld_preload`, `deleted_exe`,
`input_snooper`, `credential_access`, `stealth_network`, and `egress`;
Python remains the production agent. Python remains the production agent.
- **Phase 2 — eBPF via `cilium/ebpf`.** Port exec/syscall rules; drop the - **Phase 2 — eBPF via `cilium/ebpf`.** Port exec/syscall rules; drop the
bcc/Python runtime dependency; single static binary. bcc/Python runtime dependency; single static binary.

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@ -7,11 +7,13 @@ behavioral oracle until every subsystem reaches fixture and red-team parity.
Current scope: Current scope:
- standard-library-only flat TOML loading for the settings used so far; - standard-library-only flat TOML loading for the settings used so far;
- an injectable `/proc` process snapshot boundary; - an injectable `/proc` process/file-descriptor snapshot plus fail-open `ss`
socket collection;
- a cancellable sweep loop that emits JSONL `enodia.event.v1` records; - a cancellable sweep loop that emits JSONL `enodia.event.v1` records;
- exact `enodia.alert.v1` parity for `ld_preload` (SID `100011`), - exact `enodia.alert.v1` parity for `ld_preload` (SID `100011`),
`deleted_exe` (`100012`), `input_snooper` (`100032`), and `deleted_exe` (`100012`), `input_snooper` (`100032`), and
`credential_access` (`100033`); `credential_access` (`100033`), plus `reverse_shell` (`100010`), `egress`
(`100016`), and `stealth_network` (`100036`);
- `enodia.status.v1` heartbeat records with no persistence or retained-alert - `enodia.status.v1` heartbeat records with no persistence or retained-alert
claims; claims;
- a shared fixture checked against the Python detector by - a shared fixture checked against the Python detector by

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@ -57,6 +57,12 @@ func (a *Agent) Sweep() ([]map[string]any, error) {
timestamp := a.Now().Local().Format(time.RFC3339Nano) timestamp := a.Now().Local().Format(time.RFC3339Nano)
alerts := make([]model.Alert, 0) alerts := make([]model.Alert, 0)
// Preserve the relative order of Python detectors.REGISTRY. Snapshot and
// parity consumers rely on stable alert ordering even while unported slots
// are temporarily absent from the Go implementation.
if a.Config.Enabled("reverse_shell") {
alerts = append(alerts, detectors.ReverseShell(state, a.Config)...)
}
if a.Config.Enabled("ld_preload") { if a.Config.Enabled("ld_preload") {
alerts = append(alerts, detectors.LDPreload(state)...) alerts = append(alerts, detectors.LDPreload(state)...)
} }
@ -69,6 +75,12 @@ func (a *Agent) Sweep() ([]map[string]any, error) {
if a.Config.Enabled("credential_access") { if a.Config.Enabled("credential_access") {
alerts = append(alerts, detectors.CredentialAccess(state, a.Config)...) alerts = append(alerts, detectors.CredentialAccess(state, a.Config)...)
} }
if a.Config.Enabled("stealth_network") {
alerts = append(alerts, detectors.StealthNetwork(state, a.Config)...)
}
if a.Config.Enabled("egress") {
alerts = append(alerts, detectors.Egress(state, a.Config)...)
}
events := make([]map[string]any, 0, len(alerts)+1) events := make([]map[string]any, 0, len(alerts)+1)
for _, alert := range alerts { for _, alert := range alerts {
record, err := schema.Build("alert", alert, host, timestamp) record, err := schema.Build("alert", alert, host, timestamp)

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@ -11,6 +11,8 @@ import (
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model" "codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
) )
func intPointer(value int) *int { return &value }
func TestRunOnceEmitsAlertAndStatusEnvelopes(t *testing.T) { func TestRunOnceEmitsAlertAndStatusEnvelopes(t *testing.T) {
agent := New(config.Default(), func() (model.State, error) { agent := New(config.Default(), func() (model.State, error) {
return model.State{Processes: []model.Process{ return model.State{Processes: []model.Process{
@ -57,19 +59,34 @@ func TestSweepPreservesPythonDetectorOrder(t *testing.T) {
agent := New(config.Default(), func() (model.State, error) { agent := New(config.Default(), func() (model.State, error) {
return model.State{ return model.State{
LDPreload: "/tmp/global.so", LDPreload: "/tmp/global.so",
Processes: []model.Process{{ Processes: []model.Process{
{
PID: 42, PID: 42,
Comm: "dropper", Comm: "dropper",
Exe: "/tmp/dropper (deleted)", Exe: "/tmp/dropper (deleted)",
FDTargets: map[string]string{"4": "/etc/shadow", "7": "/dev/input/event3"}, FDTargets: map[string]string{"4": "/etc/shadow", "7": "/dev/input/event3"},
}}, },
{
PID: 100,
Comm: "bash",
Cmdline: "bash -i",
FDTargets: map[string]string{"0": "socket:[999]"},
},
},
Sockets: []model.Socket{
{State: "ESTAB", Local: "127.0.0.1:55", Peer: "9.9.9.9:443", Inode: intPointer(999), Comm: "bash", PID: intPointer(100), Kind: "tcp"},
{State: "ESTAB", Local: "10.0.0.2:5000", Peer: "8.8.8.8:4443", Comm: "hoxha", PID: intPointer(340), Kind: "sctp"},
},
}, nil }, nil
}) })
events, err := agent.Sweep() events, err := agent.Sweep()
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
} }
want := []string{"ld_preload", "deleted_exe", "input_snooper", "credential_access"} want := []string{
"reverse_shell", "ld_preload", "deleted_exe", "input_snooper",
"credential_access", "stealth_network", "egress",
}
if len(events) != len(want)+1 { if len(events) != len(want)+1 {
t.Fatalf("unexpected events: %#v", events) t.Fatalf("unexpected events: %#v", events)
} }

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@ -30,6 +30,20 @@ var defaultCredentialAccessAllowComms = []string{
"chrome", "google-chrome", "brave", "brave-browser", "chrome", "google-chrome", "brave", "brave-browser",
} }
var defaultInterpreters = []string{
"bash", "sh", "dash", "zsh", "ksh", "ash", "nc", "ncat", "netcat",
"socat", "telnet", "python", "python2", "python3", "perl", "ruby",
"php", "lua", "awk",
}
// These defaults intentionally duplicate the Python Config values. The parity
// harness catches detector output drift, while config tests catch tuning drift
// before a detector ever runs.
var defaultStealthNetworkAllowComms = []string{
"NetworkManager", "systemd-networkd", "wpa_supplicant", "dhcpcd",
"tcpdump", "dumpcap", "wireshark", "suricata", "zeek",
}
// Config mirrors the Phase 1 settings consumed by the Go sweep loop. More // Config mirrors the Phase 1 settings consumed by the Go sweep loop. More
// fields are added as their detectors are ported. // fields are added as their detectors are ported.
type Config struct { type Config struct {
@ -39,6 +53,10 @@ type Config struct {
InputSnooperAllowComms map[string]bool InputSnooperAllowComms map[string]bool
CredentialAccessAllowComms map[string]bool CredentialAccessAllowComms map[string]bool
CredentialAccessExtraPaths []string CredentialAccessExtraPaths []string
Interpreters map[string]bool
EgressAllowCIDRs []string
StealthNetworkAllowComms map[string]bool
StealthNetworkAllowKinds map[string]bool
} }
// Default returns Python-compatible defaults for the fields currently used. // Default returns Python-compatible defaults for the fields currently used.
@ -54,6 +72,10 @@ func Default() Config {
InputSnooperAllowComms: stringSet(defaultInputSnooperAllowComms), InputSnooperAllowComms: stringSet(defaultInputSnooperAllowComms),
CredentialAccessAllowComms: stringSet(defaultCredentialAccessAllowComms), CredentialAccessAllowComms: stringSet(defaultCredentialAccessAllowComms),
CredentialAccessExtraPaths: []string{}, CredentialAccessExtraPaths: []string{},
Interpreters: stringSet(defaultInterpreters),
EgressAllowCIDRs: []string{},
StealthNetworkAllowComms: stringSet(defaultStealthNetworkAllowComms),
StealthNetworkAllowKinds: map[string]bool{},
} }
} }
@ -125,6 +147,32 @@ func Load(path string) (Config, error) {
return Config{}, fmt.Errorf("credential_access_extra_paths: %w", err) return Config{}, fmt.Errorf("credential_access_extra_paths: %w", err)
} }
cfg.CredentialAccessExtraPaths = paths cfg.CredentialAccessExtraPaths = paths
case "interpreters":
// Keep arrays as sets where membership is the runtime operation. TOML
// order has no behavioral meaning for allowlists.
names, err := stringArray(value)
if err != nil {
return Config{}, fmt.Errorf("interpreters: %w", err)
}
cfg.Interpreters = stringSet(names)
case "egress_allow_cidrs":
cidrs, err := stringArray(value)
if err != nil {
return Config{}, fmt.Errorf("egress_allow_cidrs: %w", err)
}
cfg.EgressAllowCIDRs = cidrs
case "stealth_network_allow_comms":
names, err := stringArray(value)
if err != nil {
return Config{}, fmt.Errorf("stealth_network_allow_comms: %w", err)
}
cfg.StealthNetworkAllowComms = stringSet(names)
case "stealth_network_allow_kinds":
kinds, err := stringArray(value)
if err != nil {
return Config{}, fmt.Errorf("stealth_network_allow_kinds: %w", err)
}
cfg.StealthNetworkAllowKinds = stringSet(kinds)
} }
} }
return cfg, nil return cfg, nil

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@ -31,6 +31,10 @@ detectors = [
input_snooper_allow_comms = ["Xorg"] input_snooper_allow_comms = ["Xorg"]
credential_access_allow_comms = ["firefox"] credential_access_allow_comms = ["firefox"]
credential_access_extra_paths = ["/srv/secrets/"] credential_access_extra_paths = ["/srv/secrets/"]
interpreters = ["bash", "python3"]
egress_allow_cidrs = ["203.0.113.0/24"]
stealth_network_allow_comms = ["tcpdump"]
stealth_network_allow_kinds = ["mptcp"]
unknown_future_key = true unknown_future_key = true
`) `)
if err := os.WriteFile(path, raw, 0o600); err != nil { if err := os.WriteFile(path, raw, 0o600); err != nil {
@ -53,6 +57,13 @@ unknown_future_key = true
t.Fatalf("unexpected credential tuning: %#v %#v", t.Fatalf("unexpected credential tuning: %#v %#v",
cfg.CredentialAccessAllowComms, cfg.CredentialAccessExtraPaths) cfg.CredentialAccessAllowComms, cfg.CredentialAccessExtraPaths)
} }
if !cfg.Interpreters["bash"] || len(cfg.EgressAllowCIDRs) != 1 {
t.Fatalf("unexpected network tuning: %#v %#v", cfg.Interpreters, cfg.EgressAllowCIDRs)
}
if !cfg.StealthNetworkAllowComms["tcpdump"] || !cfg.StealthNetworkAllowKinds["mptcp"] {
t.Fatalf("unexpected stealth tuning: %#v %#v",
cfg.StealthNetworkAllowComms, cfg.StealthNetworkAllowKinds)
}
} }
func TestMissingFileKeepsDefaults(t *testing.T) { func TestMissingFileKeepsDefaults(t *testing.T) {

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@ -0,0 +1,41 @@
// SPDX-License-Identifier: GPL-3.0-or-later
package detectors
import (
"fmt"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/netutil"
)
// Egress ports interpreter-to-public-IP detection (SID 100016).
func Egress(state model.State, cfg config.Config) []model.Alert {
alerts := make([]model.Alert, 0)
for _, socket := range state.Sockets {
// Only established interpreter-owned sockets qualify. Listeners and
// connection setup states are handled by other detector families.
if socket.State != "ESTAB" || !cfg.Interpreters[socket.Comm] {
continue
}
host, port := netutil.SplitHostPort(socket.Peer)
// Private/special addresses and explicit trusted CIDRs are intentionally
// silent so routine local services and operator infrastructure stay quiet.
if !netutil.IsPublicIP(host) || netutil.IPInCIDRs(host, cfg.EgressAllowCIDRs) {
continue
}
alerts = append(alerts, model.Alert{
SID: 100016,
Severity: "HIGH",
Signature: "egress",
Classtype: "c2-exfil",
Key: fmt.Sprintf("egr:%s:%s", optionalPythonInt(socket.PID), host),
Detail: fmt.Sprintf(
"pid=%s comm=%s -> %s:%s (interpreter to public IP)",
optionalPythonInt(socket.PID), socket.Comm, host, port),
PIDs: alertPIDs(socket.PID),
})
}
return alerts
}

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@ -0,0 +1,27 @@
// SPDX-License-Identifier: GPL-3.0-or-later
package detectors
import (
"testing"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
)
func TestEgressPublicPrivateAndAllowlist(t *testing.T) {
state := model.State{Sockets: []model.Socket{
{State: "ESTAB", Peer: "8.8.8.8:443", Comm: "python3", PID: intPointer(500)},
{State: "ESTAB", Peer: "10.0.0.5:443", Comm: "python3", PID: intPointer(501)},
{State: "ESTAB", Peer: "9.9.9.9:443", Comm: "nginx", PID: intPointer(502)},
}}
alerts := Egress(state, config.Default())
if len(alerts) != 1 || alerts[0].SID != 100016 || alerts[0].Key != "egr:500:8.8.8.8" {
t.Fatalf("unexpected alerts: %#v", alerts)
}
cfg := config.Default()
cfg.EgressAllowCIDRs = []string{"8.8.8.0/24"}
if alerts := Egress(state, cfg); len(alerts) != 0 {
t.Fatalf("allowlisted egress alerted: %#v", alerts)
}
}

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@ -0,0 +1,47 @@
// SPDX-License-Identifier: GPL-3.0-or-later
package detectors
import (
"fmt"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
)
// ReverseShell ports the network-socket-on-stdio detector (SID 100010).
func ReverseShell(state model.State, cfg config.Config) []model.Alert {
// Build the inode correlation table once. A stdio socket alone could be a
// benign Unix socket; requiring the inode in the network socket view is the
// high-signal condition that distinguishes a likely reverse shell.
peerByInode := make(map[int]string)
for _, socket := range state.Sockets {
if socket.Inode != nil {
peerByInode[*socket.Inode] = fmt.Sprintf("%s -> %s", socket.Local, socket.Peer)
}
}
alerts := make([]model.Alert, 0)
for _, process := range state.Processes {
// Restrict to shells/interpreters exactly as Python does. Networked
// daemons commonly inherit sockets and must not become false positives.
if !cfg.Interpreters[process.Comm] {
continue
}
inode := stdioSocketInode(process)
if inode == nil || peerByInode[*inode] == "" {
continue
}
alerts = append(alerts, model.Alert{
SID: 100010,
Severity: "CRITICAL",
Signature: "reverse_shell",
Classtype: "c2-reverse-shell",
Key: fmt.Sprintf("rsh:%d", process.PID),
Detail: fmt.Sprintf(
"pid=%d comm=%s stdio=net-socket peer=[%s] cmd=[%s]",
process.PID, process.Comm, peerByInode[*inode], truncateRunes(process.Cmdline, 90)),
PIDs: []int{process.PID},
})
}
return alerts
}

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@ -0,0 +1,34 @@
// SPDX-License-Identifier: GPL-3.0-or-later
package detectors
import (
"testing"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
)
func intPointer(value int) *int { return &value }
func TestReverseShellRequiresInterpreterAndNetworkInode(t *testing.T) {
state := model.State{
Processes: []model.Process{
{PID: 100, Comm: "bash", Cmdline: "bash -i", FDTargets: map[string]string{"0": "socket:[999]"}},
{PID: 101, Comm: "nginx", FDTargets: map[string]string{"0": "socket:[999]"}},
{PID: 102, Comm: "bash", FDTargets: map[string]string{"0": "socket:[777]"}},
},
Sockets: []model.Socket{{
State: "ESTAB", Local: "127.0.0.1:55", Peer: "9.9.9.9:443",
Inode: intPointer(999), Comm: "bash", PID: intPointer(100), Kind: "tcp",
}},
}
alerts := ReverseShell(state, config.Default())
if len(alerts) != 1 || alerts[0].SID != 100010 || alerts[0].Key != "rsh:100" {
t.Fatalf("unexpected alerts: %#v", alerts)
}
want := "pid=100 comm=bash stdio=net-socket peer=[127.0.0.1:55 -> 9.9.9.9:443] cmd=[bash -i]"
if alerts[0].Detail != want {
t.Fatalf("unexpected detail: %q", alerts[0].Detail)
}
}

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@ -0,0 +1,67 @@
// SPDX-License-Identifier: GPL-3.0-or-later
package detectors
import (
"fmt"
"strconv"
"strings"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
)
func stdioSocketInode(process model.Process) *int {
// The Python oracle checks descriptors in 0,1,2 order and stops at the
// first socket. That ordering avoids a map-iteration-dependent alert.
for _, fd := range []string{"0", "1", "2"} {
target := process.FDTargets[fd]
if strings.HasPrefix(target, "socket:[") && strings.HasSuffix(target, "]") {
value, err := strconv.Atoi(target[8 : len(target)-1])
if err == nil {
return &value
}
}
}
return nil
}
func optionalPythonInt(value *int) string {
// Python f-strings render a missing optional integer as "None". Keys are
// stable machine contracts, so preserve that spelling rather than Go's
// default <nil> representation.
if value == nil {
return "None"
}
return strconv.Itoa(*value)
}
func optionalDisplayInt(value *int) string {
// Human-facing stealth-network details use "?" for unknown ownership even
// though the corresponding dedup key uses Python's "None" spelling.
if value == nil || *value == 0 {
return "?"
}
return strconv.Itoa(*value)
}
func alertPIDs(value *int) []int {
if value == nil || *value == 0 {
return []int{}
}
return []int{*value}
}
func truncateRunes(value string, limit int) string {
// Python slices Unicode code points, not UTF-8 bytes. Rune truncation keeps
// command details identical for non-ASCII argv values.
runes := []rune(value)
if len(runes) <= limit {
return value
}
return string(runes[:limit])
}
func socketKey(kind string, socket model.Socket) string {
return fmt.Sprintf("stealthnet:%s:%s:%s:%s",
kind, optionalPythonInt(socket.PID), socket.Local, socket.Peer)
}

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@ -0,0 +1,67 @@
// SPDX-License-Identifier: GPL-3.0-or-later
package detectors
import (
"fmt"
"strings"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/netutil"
)
var watchedSocketKinds = map[string]bool{
"raw": true, "sctp": true, "dccp": true, "packet": true,
"mptcp": true, "tipc": true, "xdp": true, "vsock": true,
}
var alwaysHighSocketKinds = map[string]bool{"raw": true, "packet": true, "xdp": true}
var activeSocketStates = map[string]bool{
"ESTAB": true, "LISTEN": true, "UNCONN": true, "CONNECTED": true,
"SYN-SENT": true, "SYN-RECV": true,
}
// StealthNetwork ports unusual socket-family detection (SID 100036).
func StealthNetwork(state model.State, cfg config.Config) []model.Alert {
alerts := make([]model.Alert, 0)
for _, socket := range state.Sockets {
kind := strings.ToLower(socket.Kind)
// TCP/UDP belong to reverse-shell, egress, and listener detectors. This
// detector is deliberately limited to less-common covert-channel paths.
if !watchedSocketKinds[kind] || cfg.StealthNetworkAllowKinds[kind] {
continue
}
if socket.Comm != "" && cfg.StealthNetworkAllowComms[socket.Comm] {
continue
}
if socket.State != "" && !activeSocketStates[socket.State] {
continue
}
severity := "MEDIUM"
host, _ := netutil.SplitHostPort(socket.Peer)
publicPeer := netutil.IsPublicIP(host) && !netutil.IPInCIDRs(host, cfg.EgressAllowCIDRs)
// Raw/packet/XDP access, listeners, and public peers are immediately
// high severity; inactive or locally scoped unusual families stay medium.
if alwaysHighSocketKinds[kind] || socket.State == "LISTEN" || publicPeer {
severity = "HIGH"
}
comm := socket.Comm
if comm == "" {
comm = "?"
}
alerts = append(alerts, model.Alert{
SID: 100036,
Severity: severity,
Signature: "stealth_network",
Classtype: "covert-channel",
Key: socketKey(kind, socket),
Detail: fmt.Sprintf(
"%s socket state=%s local=%s peer=%s comm=%s pid=%s",
kind, socket.State, socket.Local, socket.Peer, comm, optionalDisplayInt(socket.PID)),
PIDs: alertPIDs(socket.PID),
})
}
return alerts
}

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@ -0,0 +1,25 @@
// SPDX-License-Identifier: GPL-3.0-or-later
package detectors
import (
"testing"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
)
func TestStealthNetworkSeverityAndAllowlist(t *testing.T) {
state := model.State{Sockets: []model.Socket{
{State: "ESTAB", Local: "10.0.0.2:5000", Peer: "8.8.8.8:4443", Comm: "hoxha", PID: intPointer(340), Kind: "sctp"},
{State: "UNCONN", Local: "*:eth0", Peer: "*", Comm: "tcpdump", PID: intPointer(341), Kind: "packet"},
{State: "ESTAB", Local: "10.0.0.2:5", Peer: "8.8.8.8:443", Comm: "curl", PID: intPointer(342), Kind: "tcp"},
}}
alerts := StealthNetwork(state, config.Default())
if len(alerts) != 1 || alerts[0].SID != 100036 || alerts[0].Severity != "HIGH" {
t.Fatalf("unexpected alerts: %#v", alerts)
}
if alerts[0].Key != "stealthnet:sctp:340:10.0.0.2:5000:8.8.8.8:4443" {
t.Fatalf("unexpected key: %s", alerts[0].Key)
}
}

View file

@ -19,9 +19,22 @@ type Process struct {
// SystemState boundary. // SystemState boundary.
type State struct { type State struct {
Processes []Process `json:"processes"` Processes []Process `json:"processes"`
Sockets []Socket `json:"sockets"`
LDPreload string `json:"ld_preload"` LDPreload string `json:"ld_preload"`
} }
// Socket matches the Python SystemState socket view. Nil inode/PID values
// preserve ss records where ownership metadata is unavailable.
type Socket struct {
State string `json:"state"`
Local string `json:"local"`
Peer string `json:"peer"`
Inode *int `json:"inode"`
Comm string `json:"comm"`
PID *int `json:"pid"`
Kind string `json:"kind"`
}
// Alert matches enodia.alert.v1. // Alert matches enodia.alert.v1.
type Alert struct { type Alert struct {
SID int `json:"sid"` SID int `json:"sid"`

View file

@ -0,0 +1,66 @@
// SPDX-License-Identifier: GPL-3.0-or-later
// Package netutil contains stdlib address helpers matching the Python oracle.
package netutil
import (
"net/netip"
"strings"
)
var carrierGradeNAT = netip.MustParsePrefix("100.64.0.0/10")
// ParseAddr accepts brackets and IPv6 zone suffixes used by ss.
func ParseAddr(value string) (netip.Addr, bool) {
value = strings.Trim(strings.TrimSpace(value), "[]")
if index := strings.IndexByte(value, '%'); index >= 0 {
value = value[:index]
}
address, err := netip.ParseAddr(value)
return address, err == nil
}
// IsPublicIP reports globally routable addresses and excludes CGNAT.
func IsPublicIP(value string) bool {
address, ok := ParseAddr(value)
// netip's GlobalUnicast includes CGNAT, so explicitly exclude 100.64/10
// to match Python ipaddress.is_global and avoid treating carrier-local
// traffic as public C2 egress.
if !ok || !address.IsGlobalUnicast() || address.IsPrivate() ||
address.IsLoopback() || address.IsLinkLocalUnicast() {
return false
}
return !carrierGradeNAT.Contains(address)
}
// IPInCIDRs checks an address against valid same-family trust prefixes.
func IPInCIDRs(value string, cidrs []string) bool {
address, ok := ParseAddr(value)
if !ok {
return false
}
for _, raw := range cidrs {
// Invalid operator entries are ignored just like Python Config. A typo
// must not crash or disable the detector sweep.
prefix, err := netip.ParsePrefix(strings.TrimSpace(raw))
if err == nil && prefix.Addr().BitLen() == address.BitLen() && prefix.Contains(address) {
return true
}
}
return false
}
// SplitHostPort splits ss-style IPv4, IPv6, and zone-qualified endpoints.
func SplitHostPort(endpoint string) (string, string) {
endpoint = strings.TrimSpace(endpoint)
if strings.HasPrefix(endpoint, "[") {
if end := strings.Index(endpoint, "]"); end >= 0 {
return endpoint[1:end], strings.TrimPrefix(endpoint[end+1:], ":")
}
}
index := strings.LastIndex(endpoint, ":")
if index < 0 {
return "", endpoint
}
return endpoint[:index], endpoint[index+1:]
}

View file

@ -0,0 +1,36 @@
// SPDX-License-Identifier: GPL-3.0-or-later
package netutil
import "testing"
func TestPublicIPMatchesPythonCases(t *testing.T) {
for _, address := range []string{"8.8.8.8", "1.1.1.1"} {
if !IsPublicIP(address) {
t.Fatalf("expected public: %s", address)
}
}
for _, address := range []string{
"10.0.0.5", "192.168.1.1", "172.16.0.1", "127.0.0.1",
"169.254.1.1", "100.64.0.1", "::1", "not-an-ip", "",
} {
if IsPublicIP(address) {
t.Fatalf("expected non-public: %s", address)
}
}
}
func TestCIDRAndEndpointHelpers(t *testing.T) {
if !IPInCIDRs("203.0.113.55", []string{"203.0.113.0/24"}) ||
IPInCIDRs("8.8.8.8", []string{"203.0.113.0/24"}) {
t.Fatal("CIDR matching failed")
}
host, port := SplitHostPort("[2001:db8::1]:22")
if host != "2001:db8::1" || port != "22" {
t.Fatalf("unexpected IPv6 split: %q %q", host, port)
}
host, port = SplitHostPort("10.2.0.2%proton0:61877")
if host != "10.2.0.2%proton0" || port != "61877" {
t.Fatalf("unexpected zone split: %q %q", host, port)
}
}

View file

@ -4,11 +4,15 @@
package system package system
import ( import (
"context"
"os" "os"
"os/exec"
"path/filepath" "path/filepath"
"regexp"
"sort" "sort"
"strconv" "strconv"
"strings" "strings"
"time"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model" "codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
) )
@ -17,6 +21,34 @@ import (
type Paths struct { type Paths struct {
ProcRoot string ProcRoot string
LDPreloadPath string LDPreloadPath string
SocketSource func() []model.Socket
}
var (
inodePattern = regexp.MustCompile(`\bino:(\d+)`)
userPattern = regexp.MustCompile(`users:\(\("([^"]+)",pid=(\d+),fd=\d+`)
)
var socketSpecs = []struct {
args []string
kind string
}{
{[]string{"-tanep"}, "tcp"},
{[]string{"-uanep"}, "udp"},
{[]string{"-wanep"}, "raw"},
{[]string{"-Sanep"}, "sctp"},
{[]string{"-danep"}, "dccp"},
{[]string{"-0anep"}, "packet"},
{[]string{"-Manep"}, "mptcp"},
{[]string{"--tipc", "-anep"}, "tipc"},
{[]string{"--xdp", "-anep"}, "xdp"},
{[]string{"--vsock", "-anep"}, "vsock"},
}
var socketNetIDs = map[string]bool{
"tcp": true, "udp": true, "raw": true, "sctp": true, "dccp": true,
"mptcp": true, "p_raw": true, "p_dgr": true, "packet": true,
"tipc": true, "xdp": true, "vsock": true,
} }
// Capture reads process state once from procRoot. Transient per-process read // Capture reads process state once from procRoot. Transient per-process read
@ -55,12 +87,79 @@ func CaptureWithPaths(paths Paths) (model.State, error) {
}) })
} }
sort.Slice(processes, func(i, j int) bool { return processes[i].PID < processes[j].PID }) sort.Slice(processes, func(i, j int) bool { return processes[i].PID < processes[j].PID })
var sockets []model.Socket
if paths.SocketSource != nil {
sockets = paths.SocketSource()
} else {
sockets = captureSockets()
}
return model.State{ return model.State{
Processes: processes, Processes: processes,
Sockets: sockets,
LDPreload: strings.TrimSpace(readText(paths.LDPreloadPath)), LDPreload: strings.TrimSpace(readText(paths.LDPreloadPath)),
}, nil }, nil
} }
func captureSockets() []model.Socket {
result := make([]model.Socket, 0)
for _, spec := range socketSpecs {
// Python asks ss once per protocol family because several families use
// incompatible flags. Preserve that behavior instead of hiding gaps
// behind a single TCP/UDP-only invocation.
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
command := exec.CommandContext(ctx, "ss", append([]string{"-H"}, spec.args...)...)
output, err := command.Output()
cancel()
if err != nil {
// Collection is fail-open by design: a missing/unsupported ss flag
// drops only that socket family and never stops process detection.
continue
}
result = append(result, parseSS(string(output), spec.kind)...)
}
return result
}
func parseSS(text, kind string) []model.Socket {
result := make([]model.Socket, 0)
for _, line := range strings.Split(text, "\n") {
fields := strings.Fields(line)
if len(fields) < 5 {
continue
}
var state, local, peer string
// Some ss versions prefix each row with the protocol netid and some
// begin directly with state. Python accepts both layouts; Go must too.
if socketNetIDs[strings.ToLower(fields[0])] && len(fields) >= 6 {
state, local, peer = fields[1], fields[4], fields[5]
} else {
state, local, peer = fields[0], fields[3], fields[4]
}
var inode, pid *int
// Ownership is best-effort. Nil values are meaningful because Python
// serializes an unknown PID differently in keys (None) and prose (?).
if match := inodePattern.FindStringSubmatch(line); len(match) == 2 {
value, err := strconv.Atoi(match[1])
if err == nil {
inode = &value
}
}
comm := ""
if match := userPattern.FindStringSubmatch(line); len(match) == 3 {
comm = match[1]
value, err := strconv.Atoi(match[2])
if err == nil {
pid = &value
}
}
result = append(result, model.Socket{
State: state, Local: local, Peer: peer, Inode: inode,
Comm: comm, PID: pid, Kind: kind,
})
}
return result
}
func parseEnviron(raw string) map[string]string { func parseEnviron(raw string) map[string]string {
result := make(map[string]string) result := make(map[string]string)
for _, item := range strings.Split(raw, "\x00") { for _, item := range strings.Split(raw, "\x00") {

View file

@ -6,6 +6,8 @@ import (
"os" "os"
"path/filepath" "path/filepath"
"testing" "testing"
"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
) )
func TestCaptureUsesInjectableProcRoot(t *testing.T) { func TestCaptureUsesInjectableProcRoot(t *testing.T) {
@ -37,7 +39,10 @@ func TestCaptureUsesInjectableProcRoot(t *testing.T) {
if err := os.WriteFile(preload, []byte("/tmp/global.so\n"), 0o600); err != nil { if err := os.WriteFile(preload, []byte("/tmp/global.so\n"), 0o600); err != nil {
t.Fatal(err) t.Fatal(err)
} }
state, err := CaptureWithPaths(Paths{ProcRoot: root, LDPreloadPath: preload}) state, err := CaptureWithPaths(Paths{
ProcRoot: root, LDPreloadPath: preload,
SocketSource: func() []model.Socket { return []model.Socket{} },
})
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
} }
@ -55,3 +60,18 @@ func TestCaptureUsesInjectableProcRoot(t *testing.T) {
t.Fatalf("unexpected global preload: %q", state.LDPreload) t.Fatalf("unexpected global preload: %q", state.LDPreload)
} }
} }
func TestParseSSMatchesPythonShapes(t *testing.T) {
text := "tcp ESTAB 0 0 10.0.0.2:5555 8.8.8.8:443 users:((\"bash\",pid=42,fd=3)) ino:999\n"
sockets := parseSS(text, "tcp")
if len(sockets) != 1 {
t.Fatalf("unexpected sockets: %#v", sockets)
}
got := sockets[0]
if got.State != "ESTAB" || got.Local != "10.0.0.2:5555" || got.Peer != "8.8.8.8:443" {
t.Fatalf("unexpected endpoints: %#v", got)
}
if got.Inode == nil || *got.Inode != 999 || got.PID == nil || *got.PID != 42 || got.Comm != "bash" {
t.Fatalf("unexpected ownership: %#v", got)
}
}

View file

@ -1,6 +1,6 @@
#!/usr/bin/env python3 #!/usr/bin/env python3
# SPDX-License-Identifier: GPL-3.0-or-later # SPDX-License-Identifier: GPL-3.0-or-later
"""Compare the first Go detector port with the Python reference oracle.""" """Compare ported Go poll detectors with the Python reference oracle."""
from __future__ import annotations from __future__ import annotations
import json import json
@ -19,15 +19,33 @@ from enodia_sentinel.config import Config # noqa: E402
from enodia_sentinel.detectors import ( # noqa: E402 from enodia_sentinel.detectors import ( # noqa: E402
credential_access, credential_access,
deleted_exe, deleted_exe,
egress,
input_snooper, input_snooper,
ld_preload, ld_preload,
reverse_shell,
stealth_network,
) )
from enodia_sentinel.system import SystemState # noqa: E402 from enodia_sentinel.system import Socket, SystemState # noqa: E402
HOST = "parity-host" HOST = "parity-host"
TIMESTAMP = "2026-07-10T00:00:00-07:00" TIMESTAMP = "2026-07-10T00:00:00-07:00"
class FixtureProcess(SimpleNamespace):
"""Duck-typed Python Process with Go-fixture stdio socket semantics."""
def stdio_socket_inode(self):
# Match Process.stdio_socket_inode: descriptors 0/1/2 only, in order.
for fd in ("0", "1", "2"):
target = self.fd_targets.get(fd, "")
if target.startswith("socket:[") and target.endswith("]"):
try:
return int(target[8:-1])
except ValueError:
continue
return None
def main() -> int: def main() -> int:
fixture = ROOT / "tests/fixtures/go/process-detectors.json" fixture = ROOT / "tests/fixtures/go/process-detectors.json"
fixture_data = json.loads(fixture.read_text()) fixture_data = json.loads(fixture.read_text())
@ -55,17 +73,21 @@ def main() -> int:
process = dict(raw_process) process = dict(raw_process)
process.setdefault("environ", {}) process.setdefault("environ", {})
process.setdefault("fd_targets", {}) process.setdefault("fd_targets", {})
processes.append(SimpleNamespace(**process)) processes.append(FixtureProcess(**process))
sockets = [Socket(**item) for item in fixture_data.get("sockets", [])]
cfg = Config() cfg = Config()
state = SystemState(processes=processes, sockets=[]) state = SystemState(processes=processes, sockets=sockets)
alerts = list(reverse_shell.detect(state, cfg))
with patch.object(ld_preload, "Path") as path_class: with patch.object(ld_preload, "Path") as path_class:
preload = path_class.return_value preload = path_class.return_value
preload.is_file.return_value = bool(fixture_data.get("ld_preload")) preload.is_file.return_value = bool(fixture_data.get("ld_preload"))
preload.read_text.return_value = fixture_data.get("ld_preload", "") preload.read_text.return_value = fixture_data.get("ld_preload", "")
alerts = list(ld_preload.detect(state, cfg)) alerts.extend(ld_preload.detect(state, cfg))
alerts.extend(deleted_exe.detect(state, cfg)) alerts.extend(deleted_exe.detect(state, cfg))
alerts.extend(input_snooper.detect(state, cfg)) alerts.extend(input_snooper.detect(state, cfg))
alerts.extend(credential_access.detect(state, cfg)) alerts.extend(credential_access.detect(state, cfg))
alerts.extend(stealth_network.detect(state, cfg))
alerts.extend(egress.detect(state, cfg))
python_alerts = [ python_alerts = [
event.from_alert(alert, host=HOST, timestamp=TIMESTAMP) event.from_alert(alert, host=HOST, timestamp=TIMESTAMP)
for alert in alerts for alert in alerts

View file

@ -1,6 +1,7 @@
{ {
"ld_preload": "/tmp/global.so\n/opt/second.so", "ld_preload": "/tmp/global.so\n/opt/second.so",
"processes": [ "processes": [
{"pid": 100, "comm": "bash", "cmdline": "bash -i", "exe": "/usr/bin/bash", "fd_targets": {"0": "socket:[999]"}},
{"pid": 200, "comm": "sleep", "cmdline": "sleep", "exe": "/usr/bin/sleep", "environ": {"LD_PRELOAD": "/tmp/evil.so"}}, {"pid": 200, "comm": "sleep", "cmdline": "sleep", "exe": "/usr/bin/sleep", "environ": {"LD_PRELOAD": "/tmp/evil.so"}},
{"pid": 201, "comm": "safe", "cmdline": "safe", "exe": "/usr/bin/safe", "environ": {"LD_PRELOAD": "/usr/lib/libfoo.so"}}, {"pid": 201, "comm": "safe", "cmdline": "safe", "exe": "/usr/bin/safe", "environ": {"LD_PRELOAD": "/usr/lib/libfoo.so"}},
{"pid": 300, "comm": "tmpdrop", "cmdline": "tmpdrop", "exe": "/tmp/x (deleted)"}, {"pid": 300, "comm": "tmpdrop", "cmdline": "tmpdrop", "exe": "/tmp/x (deleted)"},
@ -12,5 +13,11 @@
{"pid": 330, "comm": "hoxha", "cmdline": "hoxha", "exe": "/tmp/hoxha", "fd_targets": {"4": "/etc/shadow"}}, {"pid": 330, "comm": "hoxha", "cmdline": "hoxha", "exe": "/tmp/hoxha", "fd_targets": {"4": "/etc/shadow"}},
{"pid": 331, "comm": "collector", "cmdline": "collector", "exe": "/tmp/collector", "fd_targets": {"5": "/home/luna/.ssh/id_ed25519"}}, {"pid": 331, "comm": "collector", "cmdline": "collector", "exe": "/tmp/collector", "fd_targets": {"5": "/home/luna/.ssh/id_ed25519"}},
{"pid": 332, "comm": "firefox", "cmdline": "firefox", "exe": "/usr/lib/firefox/firefox", "fd_targets": {"8": "/home/luna/.mozilla/firefox/a/key4.db"}} {"pid": 332, "comm": "firefox", "cmdline": "firefox", "exe": "/usr/lib/firefox/firefox", "fd_targets": {"8": "/home/luna/.mozilla/firefox/a/key4.db"}}
],
"sockets": [
{"state": "ESTAB", "local": "127.0.0.1:55", "peer": "9.9.9.9:443", "inode": 999, "comm": "bash", "pid": 100, "kind": "tcp"},
{"state": "ESTAB", "local": "10.0.0.2:5000", "peer": "8.8.8.8:4443", "inode": 1, "comm": "hoxha", "pid": 340, "kind": "sctp"},
{"state": "UNCONN", "local": "*:eth0", "peer": "*", "inode": 2, "comm": "tcpdump", "pid": 341, "kind": "packet"},
{"state": "ESTAB", "local": "10.0.0.2:6000", "peer": "10.0.0.5:443", "inode": 3, "comm": "python3", "pid": 342, "kind": "tcp"}
] ]
} }