According to the FBI’s March 12 cybersecurity advisory (AA25-071A), over 300 critical infrastructure targets have already been affected. The attackers often pair this technique with social engineering and unpatched software vulnerabilities to devastating effect.
Why This Attack Works
The core of this threat lies in exploiting how digital systems trust expired security certificates. A certificate that expired in 2020, for example, could be used again if the system clock is rolled back to 2019. Since systems use certificate dates to validate software, this trick can make malware appear completely legitimate.
As Kurt explains, “This kind of strategy challenges the way we think about security. It is not just about building stronger defenses but also about questioning the default assumptions built into the technology we use every day.”
5 Ways to Defend Against Time-Traveling Hackers
To guard against these sophisticated attacks, both the FBI and Kurt the CyberGuy recommend several key strategies:
- Use strong antivirus software
“A strong antivirus isn’t just for catching old-school viruses anymore,” Kurt writes. It can block malicious downloads, stop ransomware, and detect phishing links. Since groups like Medusa use fake updates and clever tricks, antivirus software provides a critical first line of defense. Check Kurt’s picks for top antivirus programs of 2025. - Enable two-factor authentication (2FA)
The FBI specifically advises turning on 2FA, especially for critical systems like VPNs and webmail. 2FA greatly reduces the chance of unauthorized access, even if a hacker has your credentials. - Use strong, unique passwords
Many attacks rely on reused or weak passwords. A password manager can generate and store complex, unique passwords for each account. Kurt notes, “Get more details about my best expert-reviewed password managers of 2025 here.” - Monitor for suspicious system time changes
Since these attacks rely on rolling back the system clock, detecting and logging such changes is essential. Organizations should implement monitoring tools that flag unexpected clock modifications. - Keep systems updated and patch known vulnerabilities
Medusa’s campaigns often target systems with outdated software or unpatched bugs. Regularly installing updates for your operating system, drivers, and applications is one of the most effective defenses.
A New Era of Cyber Threats
This type of attack represents a shift in how hackers operate. Rather than brute-force or traditional exploitation, they’re now targeting the foundational logic that computer systems rely on.
