SSH Command Tracking Guide

Detail of command execution auditing and tracking across human SSH sessions and AI agent sessions (amux).

Part 1: Arch Linux (ul, bmo95, studio-kvm-ssh)

The Linux Audit Framework (auditd) captures execve system calls triggered by human user sessions (auid >= 1000), recording all interactive and SSH payload commands while strictly filtering out background system and rootless Podman container noise.

1. Installation & Service Setup

Install the audit package and enable the auditd daemon:

$ sudo pacman -S --noconfirm audit
$ sudo systemctl enable --now auditd

2. Configuration Rules & Interactive User Filtering

Create /etc/audit/rules.d/execve.rules with Audit User ID filtering (auid >= 1000):

CRITICAL: Do NOT include catch-all execve rules without -F auid>=1000. Background system daemons and rootless Podman containers started by user@1100.service (e.g. MinIO healthchecks, Authentik workers) have auid = 4294967295 (unset). An unfiltered rule generates ~8 MB of log noise every 7 minutes, rotating out entire log histories within 30 minutes.

$ sudo tee /etc/audit/rules.d/execve.rules > /dev/null << 'EOF'
# Delete pre-existing rules
-D

# Set kernel buffer size
-b 8192

# Log all command executions strictly for human/login users (auid >= 1000)
-a always,exit -F arch=b64 -S execve -F auid>=1000 -k remote_commands
-a always,exit -F arch=b32 -S execve -F auid>=1000 -k remote_commands
EOF

Load rules into the active kernel:

$ sudo auditctl -D && sudo augenrules --load
$ sudo auditctl -e 1

Verify active rules:

$ sudo auditctl -l

Process UID (uid) vs Audit User ID (auid)

• Process UID (uid=1100 docker-data & subordinate 624288–689823): Controls unprivileged host kernel UIDs for rootless Podman containers.
• Audit User ID (auid / loginuid): Assigned exclusively by PAM when a human authenticates via SSH or TTY (auid = 1000). Background containers started via systemd lingering (user@1100.service) have auid = 4294967295 (unset).
• Result: Filter by auid >= 1000.

Part 2: Agent Execution Auditing (amux / systemd journal)

When AI agents or automated scripts run multi-line code via write-pane -f <file> or write-pane -b <base64> in amux, those commands can bypass standard auditd execve logging (because they are streamed directly into an already-running shell's PTY or an interactive Python/Node REPL).

To ensure complete, tamper-resistant auditing and forensic recovery:

1. Structured Journal Logging

Every call to write-pane in amux automatically logs directly into the systemd journal with structured fields:

• SYSLOG_IDENTIFIER=amux
• AMUX_PANE_ID: Target pane (%0, %1, etc.)
• AMUX_WINDOW_NAME: Hierarchical task window (e.g. mc-pokelovers-bluemap)
• AMUX_SOURCE: Original script file path or base64
• AMUX_ARCHIVE_PATH: Permanent snapshot location in /data/amux/scripts/
• AMUX_PAYLOAD_SIZE: Injected byte count

Querying agent execution logs:

# Stream live agent injections
$ journalctl -t amux -f

# Inspect detailed metadata for recent agent commands
$ journalctl -t amux -n 20 -o verbose

2. Permanent Script Archival (/data/amux/scripts/)

Before any byte is written to the terminal PTY, amux automatically saves a bit-for-bit snapshot to:

/data/amux/scripts/YYYY-MM-DD_HHMM.SS_<window_name>.sh

• Durability: Stored on /data with ownership luke:luke.
• Zero Loss: Even if an agent immediately removes a temporary file from /dev/shm after execution, the exact script executed is preserved permanently.
• Disaster Recovery: /data/amux/scripts/ is automatically backed up during the daily backup run via /home/luke/git/backups/ul/scripts/backup/amux.

Part 3: Python Command Inspection & Summarization (audit-log)

The /usr/local/bin/audit-log Python utility parses, decodes, and summarizes EXECVE records from /var/log/audit/audit.log.*.

CLI Command Options & Usage

# 1. Default view: last 20 executed commands
$ audit-log

# 2. View specific number of entries (e.g. last 50 commands)
$ audit-log 50
$ audit-log -n 50

# 3. Stream all recorded command history
$ audit-log all
$ audit-log --all

# 4. Filter by specific day (YYYY-MM-DD)
$ audit-log --day 2026-08-29

# 5. Filter date range (since date / until date)
$ audit-log --since 2026-08-25 --clean

# 6. Filter repetitive background noise (tmux status bars, pollers)
$ audit-log --clean -n 30

# 7. Regex / substring search across command history
$ audit-log --search "funkwhale|podman" --clean

# 8. Deduplicate identical commands in output
$ audit-log --unique --since 2026-08-28

# 9. Generate automated daily change log summary outline
$ audit-log --daily --since 2026-08-25 --clean

Part 4: OpenBSD (Router danknasty)

OpenBSD uses native kernel process accounting (acct) to track binary executions, alongside syslog-based sshd verbose logging and doas auditing.

1. Kernel Process Accounting (acct)

Enable Accounting:

# Create log file
$ doas touch /var/account/acct

# Enable accounting at boot
$ echo "accounting=YES" | doas tee -a /etc/rc.conf.local

# Start accounting daemon immediately
$ doas /usr/sbin/accton /var/account/acct

2. Real-Time Command Inspection (audit-log)

Query process execution history using the matching audit-log helper script:

# View the last 20 executed commands (Default)
$ doas audit-log

# View a specific number of recent commands (e.g. 50 entries)
$ doas audit-log 50

# View ALL recorded command history
$ doas audit-log all

3. SSH Verbose Payload & doas Logging

To log non-interactive SSH connections and payload commands to /var/log/authlog:

1. Edit /etc/ssh/sshd_config:

   LogLevel VERBOSE
   

2. Reload sshd:

   $ doas rcctl reload sshd
   

3. Monitor logs:

   $ doas tail -f /var/log/authlog