Fog Ransomware Exposes Active Directory Exploitation Toolkit in Open Server

Cybersecurity researchers have uncovered a publicly accessible server operated by an affiliate of the Fog ransomware group, revealing a suite of tools and scripts designed for Active Directory exploitation. The server, hosted at 194.48.154.79:80, contained reconnaissance, credential theft, lateral movement, and persistence mechanisms, according to findings by The DFIR Report’s Threat Intel Group¹. This discovery highlights the group’s evolving tactics, which include leveraging known vulnerabilities like Zerologon (CVE-2020-1472) and noPac (CVE-2021-42278) for lateral movement².

Key Findings and Attack Chain

The Fog ransomware group, first observed in April 2024, has targeted sectors such as education (19%), technology (17%), and manufacturing (15%)³. Their attack chain begins with phishing emails containing malicious ZIP attachments or exploited VPN credentials (CVE-2023-0656). Once inside, attackers deploy PowerShell scripts like stage1.ps1 and lootsubmit.ps1 to deliver payloads in memory. Persistence is achieved through startup folder modifications, often masquerading as legitimate processes like Adobe Acrobat.exe⁴.

Lateral movement relies on tools such as Cobalt Strike, NetExec, and Impacket, while data exfiltration occurs via MEGAsync or direct uploads to attacker-controlled servers. Notably, the group uses the Wigle.net API to geolocate victims based on router BSSIDs⁵.

Tools and Techniques

The open directory revealed several specialized tools:

Tool	Function
Certipy	Exploits Active Directory Certificate Services for privilege escalation
DonPAPI	Extracts DPAPI credentials from browsers and vaults
Havoc C2	Post-exploitation framework embedded in `ktool.exe`

MITRE ATT&CK mappings include T1078 (Valid Accounts) for VPN abuse and T1486 (Data Encrypted for Impact) for file encryption⁶.

Indicators of Compromise (IoCs)

Critical IoCs from the investigation include:

Payloads: SHA-256 hashes B6360765c786ceee0eb28bee64709172b4e2e066449968e011390be1afd8f36c (Fog) and 3d2cbef9be0c48c61a18f0e1dc78501ddabfd7a7663b21c4fcc9c39d48708e91 (DOGE variant)
C2 Servers: IP 194.48.154.79 (Sliver C2) and URL hxxps://hilarious-trifle-d9182e.netlify[.]app/stage1[.]ps1

Recommendations for Mitigation

Organizations should prioritize patching Zerologon and noPac vulnerabilities, enforce MFA for VPN/RDP access, and monitor for anomalous PowerShell activity. Offline backups and dark web monitoring for leaked data are also critical⁷.

Conclusion

The exposure of Fog’s toolkit underscores the group’s sophistication and reliance on publicly available exploits. With ransom demands averaging $220,000 (often in Monero), proactive defense measures are essential to mitigate risks posed by this evolving threat.