New threats emerge regularly, challenging organizations to stay vigilant and proactive. One such recent threat is FOG ransomware, a new ransomware family that has quickly gained notoriety for its sophisticated attack methods and widespread impact.
FOG ransomware first became known in early 2025, when cybersecurity researchers from Trend Micro uncovered a series of phishing campaigns distributing this malicious software. The attackers behind FOG ransomware have been known to impersonate the U.S. Department of Government Efficiency (DOGE), embedding politically themed messages in their phishing emails to deceive victims. These emails often contain ZIP archives titled “Pay Adjustment.zip,” which include LNK files masquerading as PDF documents. When these files are executed, they trigger a multi-stage infection process aimed at deploying the FOG ransomware payload.
The infection process starts with a phishing email that includes a ZIP archive containing a LNK file, which is cleverly disguised as a PDF. When the victim clicks on the LNK file, it silently executes PowerShell commands that download a script named stage1.ps1. This script triggers a series of downloads, including the primary ransomware loader (cwiper.exe), an exploit tool (ktool.exe), and data-harvesting scripts (lootsubmit.ps1 and trackerjacker.ps1. The ransomware loader examines hardware specifications, registry keys, and system behaviors to detect any anti-analysis environments. If it detects a sandbox, it halts execution; otherwise, it decrypts an embedded payload using a hardcoded key and begins encrypting the victim’s files.
Since its emergence, FOG ransomware has claimed responsibility for over 100 victims, with a noticeable spike of 53 attacks in February 2025 alone. The victims span various industries, including technology, education, manufacturing, transportation, healthcare, retail, business services, and consumer operations. The attackers have also set up a leak site to showcase their victims, adding pressure on organizations to pay the ransom.
Given the sophisticated nature of FOG ransomware, organizations must adopt robust cybersecurity practices to mitigate the risk of infection. Here are some essential steps to protect against FOG ransomware:
- Employee Training: Inform employees about the risks associated with phishing emails and emphasize the need to verify the authenticity of email attachments before opening them.
- Regular Backups: Regularly maintain system backups and store them separately from the source systems. Make sure these backups are protected from being altered or encrypted by any potentially compromised network devices.
- Patch Management: Regularly update operating systems, software, and firmware with the latest security patches to address known vulnerabilities.
- Network Segmentation: Segment networks to restrict lateral movement from initial infected devices to other devices within the organization.
- Multi-Factor Authentication (MFA): Require phishing-resistant MFA for access to all privileged accounts and email services.
- Advanced Threat Detection: Deploy advanced threat detection solutions to swiftly identify and address any suspicious activities.
FOG ransomware represents a significant threat in the cybersecurity landscape, with its sophisticated attack methods and widespread impact. By understanding how FOG ransomware operates and adopting proactive cybersecurity measures, organizations can better protect themselves against this emerging threat. Staying informed and vigilant is crucial in the fight against ransomware, ensuring that businesses can continue to operate securely in an increasingly digital world.
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