Fog ransomware is a ransomware family that the report page says was identified in April 2024. The page says it is believed to gain access through brute-force attacks on Remote Desktop Protocol and compromised VPN credentials, then delete system shadow copies to block recovery. The report covers its technical analysis.
Fog Ransomware was identified in April 2024 and is believed to utilize common initial access vectors, including brute-force attacks on Remote Desktop Protocol (RDP) and compromised Virtual Private Network (VPN) credentials.
Fog Ransomware employs rapid encryption while leveraging cross-platform compatibility and advanced cryptographic methods. Its multi-threaded execution, targeted disabling of critical services and processes, and deletion of system shadow copies indicate a calculated approach to maximizing system disruption and preventing data recovery.
Last checked against sources: October 10, 2026.
How Did Fog Ransomware Attacks Unfold in the First Reported Cases?
Arctic Wolf Labs began monitoring Fog ransomware deployments on May 2, 2024. All victims it investigated were in the United States, 80% in education and 20% in recreation. In each case the attackers entered through compromised VPN credentials, using gateways from two different VPN vendors. Inside the network they used PsExec to reach other hosts, SoftPerfect Network Scanner and Advanced Port Scanner to map the network, and SharpShares to list network shares (Arctic Wolf).
Before encrypting, the attackers ran vssadmin.exe delete shadows /all /quiet to remove shadow copies. Encrypted files received a .fog or .flocked extension and a readme.txt ransom note carried a unique chat code for each victim. Arctic Wolf did not observe data theft or a dark web leak site in those cases, so this early picture may have changed since.
How Can Organizations Defend Against Fog Ransomware?
Because access came through stolen VPN credentials, protect remote access first with multi-factor authentication and monitoring for logins that look wrong. For recovery, MITRE ATT&CK (T1490) recommends off-system backups with restricted access, and Arctic Wolf advises secure off-site backups and defense in depth so an attack is stopped as early as possible. Our ransomware glossary entry covers the wider picture.
What Will You Find in the Fog Ransomware Report?
Learn Technical Method of Operation Details
You will find the technical details of the Fog Ransomware its functions, and details about cyber attack tactics. The report will show many points about its technical details, detections, and IoCs.
Gain Knowledge About Future Attacks
By understanding its attack model, you can make more informed predictions about the future of cybersecurity. Stay up-to-date with the latest trends and keep your business from potential threats.
Response & Mitigation Tactics From Experts
Brandefense analysts share practical response and mitigation advice on this topic. The Fog Ransomware employs sophisticated techniques to avoid analysis by security researchers. You need experts’ perspective.