Description

Researchers are concerned about cy?bercriminals' abuse of Cloudflare Tunnel services to distribute remote access trojans (RATs). This activity, which was discovered in February, uses the free TryCloudflare service as an exploit to spread RATs like Xworm, GuLoader, VenomRAT, Remcos RAT, and AsyncRAT. Cloudflare Tunnel proxies traffic through an encrypted tunnel, allowing secure access to local services without exposing IP addresses. TryCloudflare enables users to create temporary tunnels to local servers without needing a Cloudflare account, generating temporary subdomains on trycloudflare.com. Cybercriminals exploit this feature to gain remote access to compromised systems while evading detection. The malware is targeting law, finance, manufacturing, and technology sectors. In these attacks, malicious .LNK files are hosted on the TryCloudflare domain, and Python installers are used to deploy the final payload. Proofpoint observed a surge in malicious email distribution, with over 1,500 messages sent in a campaign starting July 11, up from fewer than 50 messages in a May 28 wave. Hosting LNK files on Cloudflare offers advantages, such as making traffic appear legitimate due to Cloudflare's reputation. The TryCloudflare Tunnel feature also provides anonymity and temporary subdomains that are hard to block, allowing cybercriminals to avoid infrastructure costs. Automation makes it easier to perform large-scale activities by preventing Cloudflare blocks. Proofpoint and other security vendors are encouraged to submit suspicious URLs to Cloudflare for action against customers using their services for malware.