What it does. Parse and analyze Cobalt Strike Malleable C2 profiles with dissect.cobaltstrike (profiles and beacon-payload configs) and pyMalleableC2 (AST parsing) to extract HTTP/DNS transforms, URIs, headers, sleep/jitter, and injection behavior, then generate network detection signatures. Use when reverse-engineering a captured malleable profile or building detections against Cobalt Strike Beacon traffic. Part of mukul975/Anthropic-Cybersecurity-Skills (817 security skills) (mukul975/Anthropic-Cybersecurity-Skills).

Install

• npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill analyzing-cobaltstrike-malleable-c2-profiles, or copy the skill folder into ~/.claude/skills/analyzing-cobaltstrike-malleable-c2-profiles/.
• Raw file: curl -sL https://raw.githubusercontent.com/mukul975/Anthropic-Cybersecurity-Skills/HEAD/skills/analyzing-cobaltstrike-malleable-c2-profiles/SKILL.md

SKILL.md (verbatim)

name: analyzing-cobaltstrike-malleable-c2-profiles
description: Parse and analyze Cobalt Strike Malleable C2 profiles with dissect.cobaltstrike (profiles and beacon-payload configs) and pyMalleableC2 (AST parsing) to extract HTTP/DNS transforms, URIs, headers, sleep/jitter, and injection behavior, then generate network detection signatures. Use when reverse-engineering a captured malleable profile or building detections against Cobalt Strike Beacon traffic.
domain: cybersecurity
subdomain: malware-analysis
tags:
- cobalt-strike
- malleable-c2
- c2-detection
- beacon-analysis
- network-signatures
- threat-hunting
- red-team-tools
version: '1.0'
author: mahipal
license: Apache-2.0
nist_csf:
- DE.AE-02
- RS.AN-03
- ID.RA-01
- DE.CM-01
mitre_attack:
- T1071.001
- T1573.002
- T1001.003
- T1090.004
- T1102

Analyzing CobaltStrike Malleable C2 Profiles

Overview

Cobalt Strike Malleable C2 profiles are domain-specific language scripts that customize how Beacon communicates with the team server, defining HTTP request/response transformations, sleep intervals, jitter values, user agents, URI paths, and process injection behavior. Threat actors use malleable profiles to disguise C2 traffic as legitimate services (Amazon, Google, Slack). Analyzing these profiles reveals network indicators for detection: URI patterns, HTTP headers, POST/GET transforms, DNS settings, and process injection techniques. The dissect.cobaltstrike library can parse both profile files and extract configurations from beacon payloads, while pyMalleableC2 provides AST-based parsing using Lark grammar for programmatic profile manipulation and validation.

When to Use

• When investigating security incidents that require analyzing cobaltstrike malleable c2 profiles
• When building detection rules or threat hunting queries for this domain
• When SOC analysts need structured procedures for this analysis type
• When validating security monitoring coverage for related attack techniques

Prerequisites

• Python 3.9+ with dissect.cobaltstrike and/or pyMalleableC2
• Sample Malleable C2 profiles (available from public repositories)
• Understanding of HTTP protocol and Cobalt Strike beacon communication model
• Network monitoring tools (Suricata/Snort) for signature deployment
• PCAP analysis tools for traffic validation

Steps

1. Install libraries: pip install dissect.cobaltstrike or pip install pyMalleableC2
2. Parse profile with C2Profile.from_path("profile.profile")
3. Extract HTTP GET/POST block configurations (URIs, headers, parameters)
4. Identify user agent strings and spoof targets
5. Extract sleep time, jitter percentage, and DNS beacon settings
6. Analyze process injection settings (spawn-to, allocation technique)
7. Generate Suricata/Snort signatures from extracted network indicators
8. Compare profile against known threat actor profile collections
9. Extract staging URIs and payload delivery mechanisms
10. Produce detection report with IOCs and recommended network signatures

Expected Output

A JSON report containing extracted C2 URIs, HTTP headers, user agents, sleep/jitter settings, process injection config, spawned process paths, DNS settings, and generated Suricata-compatible detection rules.

Other files in this skill

• LICENSE
• references/api-reference.md
• scripts/agent.py

references/api-reference.md (verbatim)

CobaltStrike Malleable C2 Profile Analysis API Reference

Installation

pip install dissect.cobaltstrike
pip install 'dissect.cobaltstrike[full]'   # With PCAP support
pip install pyMalleableC2                   # Alternative parser

dissect.cobaltstrike API

Parse Beacon Configuration

from dissect.cobaltstrike.beacon import BeaconConfig

bconfig = BeaconConfig.from_path("beacon.bin")
print(hex(bconfig.watermark))     # 0x5109bf6d
print(bconfig.protocol)           # https
print(bconfig.version)            # BeaconVersion(...)
print(bconfig.settings)           # Full config dict

Parse Malleable C2 Profile

from dissect.cobaltstrike.c2profile import C2Profile

profile = C2Profile.from_path("amazon.profile")
config = profile.as_dict()
print(config["useragent"])
print(config["http-get.uri"])
print(config["sleeptime"])

PCAP Analysis

# Extract beacons from PCAP
beacon-pcap --extract-beacons traffic.pcap

# Decrypt traffic with private key
beacon-pcap -p team_server.pem traffic.pcap --beacon beacon.bin

pyMalleableC2 API

from malleableC2 import Profile

profile = Profile.from_file("amazon.profile")
print(profile.sleeptime)
print(profile.useragent)
print(profile.http_get.uri)
print(profile.http_post.uri)

Key Profile Settings

Suricata Rule Format

alert http $HOME_NET any -> $EXTERNAL_NET any (
  msg:"MALWARE CobaltStrike C2 URI";
  flow:established,to_server;
  http.uri; content:"/api/v1/status";
  http.header; content:"User-Agent: Mozilla/5.0";
  sid:9000001; rev:1;
)

CLI Usage

python agent.py --input profile.profile --output report.json
python agent.py --input parsed_config.json --output report.json

References

• dissect.cobaltstrike: https://github.com/fox-it/dissect.cobaltstrike
• pyMalleableC2: https://github.com/byt3bl33d3r/pyMalleableC2
• Unit42 Analysis: https://unit42.paloaltonetworks.com/cobalt-strike-malleable-c2-profile/
• Config Extractor: https://github.com/strozfriedberg/cobaltstrike-config-extractor

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