An Iranian-linked cyber-espionage group known as Tortoiseshell has enhanced its malware arsenal with newly identified tools, including a reverse SSH tunneling utility and a C++ backdoor. The SSH tunnel, disguised as wtsapi32.dll, leverages Windows OpenSSH client to establish connections with command-and-control infrastructure. The backdoor, showing similarities to TWOSTROKE malware, supports file execution, shell commands, in-memory DLL execution, and file manipulation capabilities. Infrastructure analysis revealed domains with subdomains referencing UAE, Saudi Arabia, UK, Belgium, Canada, Australia, and Japan, suggesting expanded targeting beyond the group's traditional focus on defense, aerospace, IT service providers, and military organizations in the Middle East and United States. Active since 2018, the group continues operations with persistent infrastructure despite domain suspensions.

Indicators of Compromise

• domain: locat.sbs
• domain: tiktok-u.sbs