Cybercriminals Abusing Cloudflare Tunnels to Evade Detection and Spread Malware
Aug 02, 2024
Malware / Network Security
Cybersecurity companies are warning about an uptick in the abuse of Clouflare's TryCloudflare free service for malware delivery. The activity, documented by both eSentire and Proofpoint , entails the use of TryCloudflare to create a rate-limited tunnel that acts as a conduit to relay traffic from an attacker-controlled server to a local machine through Cloudflare's infrastructure. Attack chains taking advantage of this technique have been observed delivering a cocktail of malware families such as AsyncRAT, GuLoader, PureLogs Stealer, Remcos RAT, Venom RAT, and XWorm. The initial access vector is a phishing email containing a ZIP archive, which includes a URL shortcut file that leads the message recipient to a Windows shortcut file hosted on a TryCloudflare-proxied WebDAV server. The shortcut file, in turn, executes next-stage batch scripts responsible for retrieving and executing additional Python payloads, while simultaneously displaying a decoy PDF document hosted on ...