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Introduction:
The cybersecurity landscape is witnessing a significant shift with the emergence of bespoke Command and Control (C2) frameworks developed by skilled penetration testers. The recent release of the “Conquest” C2 framework, built from scratch in the Nim programming language, exemplifies this trend, highlighting a move towards highly customizable and evasive post-exploitation tools. This development forces blue teams to understand the underlying techniques of modern C2s to effectively defend against them.
Learning Objectives:
- Understand the core components and evasion techniques of modern C2 frameworks like Conquest.
- Learn key commands for threat hunting, memory analysis, and network detection related to custom C2 traffic.
- Develop mitigation strategies against sleep obfuscation, malleable profiles, and in-memory execution.
You Should Know:
1. Identifying Nim-Based Payloads
Nim is increasingly popular for malware development due to its cross-compilation capabilities and lower detection rates. Identifying processes from compiled Nim binaries is a crucial first step.
Linux/Mac (View processes and their associated commands)
ps aux | grep -i nim
Windows (Using PowerShell to find potential Nim processes)
Get-Process | Where-Object {$<em>.Path -like "nim" -or $</em>.ProcessName -like "conquest"} | Select-Object ProcessName, Id, Path
Windows Command Prompt
tasklist | findstr /i nim
Step-by-step guide: The `ps aux` command on Unix-like systems lists all running processes; grepping for “nim” can help identify the parent compiler or a running payload. On Windows, PowerShell’s `Get-Process` cmdlet is more powerful than `tasklist` as it can inspect the full image path. These commands are your first line of detection for a potentially undetected binary.
2. Network Detection for Custom HTTP C2
Conquest uses a custom protocol over HTTP. Detecting anomalous HTTP traffic is key.
Using tcpdump to capture HTTP traffic on eth0
sudo tcpdump -i eth0 -A 'tcp port 80 and (((ip[2:2] - ((ip[bash]&0xf)<<2)) - ((tcp[bash]&0xf0)>>2)) != 0)'
Using tshark (Wireshark's CLI) to follow HTTP streams
tshark -i eth0 -Y "http" -T fields -e http.request.full_uri -e http.user_agent
PowerShell: Querying Windows Firewall Log for HTTP/HTTPS blocks (if logging is enabled)
Get-WinEvent -FilterHashtable @{LogName='Security'; ID=5152} | Where-Object {$<em>.Message -like "80" -or $</em>.Message -like "443"} | Format-List
Step-by-step guide: The `tcpdump` command captures and prints the ASCII content of packets on port 80, allowing you to inspect for non-standard HTTP headers or patterns. `tshark` provides more structured output, specifically showing the URI and User-Agent, which are often customized in C2 frameworks. The PowerShell command checks the Windows firewall log for events related to network traffic being blocked.
3. Hunting for Malleable C2 Profile Anomalies
Malleable C2 profiles allow attackers to make their traffic blend in with legitimate traffic (e.g., mimicking Google or Azure requests).
Using Suricata to write custom rules for anomalous User-Agents alert http any any -> any any (msg:"SUSPICIOUS User-Agent - Potential C2"; http.user_agent; content:"Mozilla/5.0"; distance:0; pcre:"/(?!(Windows|Linux|AppleWebKit)).Conquest|Nim/"; sid:1000001; rev:1;) Log Analysis with grep: Searching Apache/Nginx logs for known Conquest indicators grep -E '(conquest|nim|malicious.js)' /var/log/nginx/access.log PowerShell: Parsing IIS logs from a directory Get-ChildItem C:\inetpub\logs\LogFiles.log | Select-String -Pattern "conquest"
Step-by-step guide: Suricata rules can be deployed on a network sensor to alert on traffic that matches specific patterns, like a HTTP request with a common User-Agent string that also contains a framework-specific keyword. The `grep` and `Select-String` commands are for retrospective analysis of web server logs to find evidence of compromise.
4. Investigating Sleep Obfuscation Techniques
Sleep obfuscation evades sandboxes and EDRs by making a process appear inactive. Conquest features configurable sleep timers.
PowerShell: Use Get-Process to check for high "Start Time" but low CPU (potential sleep)
Get-Process | Where-Object {$<em>.CPU -lt 1 -and ((Get-Date) - $</em>.StartTime).TotalHours -gt 1} | Select-Object ProcessName, Id, CPU, StartTime
Using Sysinternals Process Explorer: Manually check the "Threads" tab of a suspicious process for threads in a Wait state.
Command line to launch Process Explorer (download from Microsoft)
procexp.exe
Step-by-step guide: The PowerShell command identifies processes that have been running for a long time but have consumed almost no CPU, a potential indicator of a sleeping process. For a deeper, real-time analysis, Sysinternals Process Explorer is an essential GUI tool where you can inspect individual thread states and stack traces.
5. Detecting In-Memory .NET Assembly Loads
Conquest can execute .NET assemblies directly in memory, bypassing disk-based AV scans.
PowerShell: Monitor Event ID 4688 (Process Creation) for .NET related modules loaded by non-standard parents
Get-WinEvent -FilterHashtable @{LogName='Security'; ID=4688} | Where-Object {$<em>.Message -like "mscoree.dll" -and $</em>.Message -notlike "VisualStudio"} | Format-List
Using Sysmon (Configuration required): A custom rule to log module loads (Event ID 7)
Example Sysmon config snippet:
<RuleGroup groupRelation="or">
<ImageLoad onmatch="include">
<Image condition="contains">mscoree.dll</Image>
</ImageLoad>
</RuleGroup>
Step-by-step guide: Native Windows logging (Event ID 4688) can be queried for the loading of key .NET libraries like `mscoree.dll` by unexpected parent processes. For more robust detection, Sysmon should be configured to log module load events (Event ID 7), providing a detailed audit trail of in-memory execution.
6. Analyzing Token Manipulation Privilege Escalation
Post-exploitation modules often include token manipulation for privilege escalation (e.g., SeDebugPrivilege).
Windows: Check current process tokens using whoami
whoami /priv
PowerShell: Get a detailed list of privileges for all processes
Get-Process | ForEach-Object { $proc = $_; $<em>.Modules | Where-Object {$</em>.ModuleName -like "ntdll.dll"} | ForEach-Object { Write-Output "$($proc.ProcessName) : $($proc.Id)" } } This is a complex check. A simpler one is:
Get-WinEvent -LogName Security | Where-Object {$<em>.Id -eq 4672 -and $</em>.Message -like "SeDebugPrivilege"} | Format-List
Using Sysinternals Process Explorer: Check the "Security" tab of a process to see its enabled privileges.
Step-by-step guide: The `whoami /priv` command shows the privileges of your current console session. To hunt for abuse, you can search the Security event log for Event ID 4672 (Special privileges assigned to new logon) looking for high-risk privileges like `SeDebugPrivilege` being assigned. Process Explorer provides a real-time, graphical view.
7. Memory Analysis for COFF/BOF Payloads
Conquest supports loading Compiled Object Files (COFF) and Beacon Object Files (BOF), which run directly in a beacon’s memory.
Using Volatility 3 to analyze a memory dump for suspicious shellcode regions vol -f memory.dmp windows.malfind.Malfind Using Volatility 3 to list processes vol -f memory.dmp windows.pslist.PsList Dumping a specific process for deeper analysis vol -f memory.dmp windows.dumpfiles --pid 1234 --physaddr
Step-by-step guide: After acquiring a memory dump (e.g., with DumpIt or WinPMEM), use the Volatility framework. The `malfind` plugin is specifically designed to find hidden and injected code in process memory, which is exactly how COFF/BOF files operate. You can then use `pslist` to get a process list and `dumpfiles` to extract the malicious code for further analysis.
What Undercode Say:
- The democratization of advanced C2 development lowers the barrier for sophisticated attacks, moving beyond well-known frameworks like Cobalt Strike.
- Defenders must pivot from signature-based detection to behavior and anomaly-focused hunting, focusing on protocol anomalies, memory artifacts, and token misuse.
The release of Conquest is not an isolated event but part of a broader trend where offensive security professionals are building custom tools to bypass commercial security solutions. This framework’s use of Nim, sleep obfuscation, and malleable profiles represents the new baseline for evasion. The critical analysis for defenders is that reliance on static IoCs is becoming obsolete. The focus must shift to deep behavioral monitoring, including detailed process lineage analysis, network traffic baselining, and memory forensics readiness. The defensive playbook now requires understanding the core techniques these frameworks use, rather than just their names.
Prediction:
The proliferation of bespoke, minimally-detected C2 frameworks like Conquest will accelerate, forcing a fundamental change in defensive cybersecurity. AI-powered security tools will soon be required to baseline normal system behavior at an unprecedented granularity—tracking thread execution, API call sequences, and memory allocation patterns—to detect the subtle anomalies left by these evasive tools. The cat-and-mouse game will escalate from the network perimeter to the very core of the operating system’s execution layers.
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IT/Security Reporter URL:
Reported By: Jakobfriedl Bsidesvienna – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
