JPCERT Shares Tips for Detecting Ransomware Attacks Using Windows Event Logs

 

Japan’s Computer Emergency Response Center (JPCERT/CC) recently revealed strategies to detect ransomware attacks by analyzing Windows Event Logs, offering vital early detection before the attack spreads. JPCERT’s insights focus on identifying digital traces left behind by ransomware within four key types of event logs: Application, Security, System, and Setup logs. These logs reveal valuable clues about the entry points used by attackers and can assist in quicker mitigation. Ransomware attacks often target system vulnerabilities and attempt to encrypt files, delete backups, or modify network settings, leaving detectable traces within the event logs. 

For example, the notorious Conti ransomware can be recognized by multiple event logs connected to the Windows Restart Manager, showing event IDs 10000 and 10001. Other ransomware variants like Akira, Lockbit3.0, and HelloKitty, which share similar encryptor technology, leave comparable logs. Additionally, ransomware such as Phobos records when system backups are deleted, a key indicator of malicious activity. Detecting these logs promptly allows administrators to intervene before damage escalates. Midas ransomware, known for spreading infection via network changes, logs event ID 7040. Similarly, BadRabbit leaves event ID 7045 when installing its encryption component, while Bisamware logs events during the beginning and end of a Windows Installer transaction (event IDs 1040 and 1042). 

Other ransomware strains, like Shade, GandCrab, and Vice Society, create errors related to accessing COM applications and deleting Volume Shadow Copies, which are pivotal for restoring encrypted data. JPCERT’s findings illustrate that monitoring for these specific event IDs in combination with a broader security framework could be a game-changer in ransomware defense. Though older ransomware variants like WannaCry and Petya left no such traces in Windows logs, modern ransomware often does. As a result, tracking these logs offers an effective layer of protection against new threats, helping to prevent encryption and data loss. 

It is important to note that no single method of detection is foolproof. A multi-layered approach that combines monitoring event logs with other security tools and protocols remains crucial for protecting systems from ransomware attacks. By using this event log analysis strategy, organizations can significantly reduce the chances of ransomware spreading undetected, giving them the edge in stopping an attack before it cripples their network.