Chinese ransomware uses Google Docs form to share encryption keys
Researchers have discovered a new strain of ransomware that uses Google Docs to avoid detection.
The module – dubbed ‘cuteRansomware’ – was found by cloud security firm Netskope. It appears to be a Chinese variant of the ‘my-Little-Ransomware’ package, which was published on GitHub some months ago.
Most of the source code remains unchanged from the original ransomware sample, aside from a few notable alterations.
Firstly, the list of file extensions sought out and encrypted by cuteRansomware was much smaller than the original malware, including .bmp, .png, .jpg, .zip, .txt, .pdf, .pptx, .docx, .py, .cpp, .pcap, .enc, .pem, and .csr files.
More importantly, however, once infected, the modified ransomware used a Google Docs form to send the attacker the victim’s computer’s name and the RSA encryption keys used for encrypting their files.
By using Google Docs as a data transmission vector, the attackers can use Google’s own security to circumvent the victim’s security, the company warned.
“Google Docs uses HTTPS by default and the network data transmission over SSL can easily bypass traditional security solutions such as a firewall, intrusion prevention system, or next generation firewall,” Netskope wrote in a blog post. “We believe this is critical.”
“As malicious actors make increasing use of the cloud for both delivering malware and exfiltrating data via command-and-control, traditional detection tools’ lack of visibility into SSL becomes a huge benefit to them.”
Netskope also stated that this could represent the start of a trend towards increasing use of cloud services in amongst malware authors, for controlling botnets as well as conveying information.
The security firm said it has notified Google’s own security team of the issue. IT Pro has contacted Google for comment.