Iran-linked hackers expand infrastructure across Europe and Middle East, report says
Group-IB found Iran-linked Tortoiseshell expanding command-and-control infrastructure into the UK, Belgium, Saudi Arabia and the UAE with new malware tooling.
Group-IB researchers identified new Tortoiseshell command-and-control infrastructure, including servers named 'uk1' and 'uk2' hosted on UK IP addresses, plus systems in Belgium, Saudi Arabia and the UAE. The Iran-linked espionage group, active since at least 2018 and previously tied to the Islamic Revolutionary Guard Corps, has historically targeted defense, aerospace, technology and military organizations in the Middle East and the United States. Researchers also uncovered new malware samples, including a backdoor resembling TwoStroke that enables command execution, file theft and system reconnaissance, and a tool establishing reverse SSH tunnels to attacker-controlled servers. Group-IB assesses that the group is expanding both its geographic reach and its capabilities and ranks it among the most active Iranian APTs of 2026.
Nimbus Manticore Expands Toolset With TWOSTROKE
Group-IB found new infrastructure and TWOSTROKE-like malware used by IRGC-linked Nimbus Manticore, indicating expanded Middle East and Europe targeting.
Group-IB reported new Tortoiseshell infrastructure spanning Europe and the Middle East and two previously undocumented tools from IRGC-linked Nimbus Manticore (UNC1549): a reverse SSH tunneling utility connecting to 172.86.98.113 on port 443, and a C++ backdoor masquerading as wtsapi32.dll with three hard-coded C2 servers. The backdoor overlaps with TWOSTROKE and supports file transfer, execution, host information gathering, and persistence. Findings build on Kaspersky's report of the NightLedger backdoor and WebSocket tunnelers BridgeHead and ArcBridge, and suggest expanded targeting beyond the Middle East into Europe.
Tortoiseshell Expands Malware Toolset With New Backdoor, SSH Tunnel
Group-IB uncovered new infrastructure linked to the Tortoiseshell threat actor, including an additional backdoor and an SSH tunneling tool.
Group-IB researchers have discovered new Tortoiseshell infrastructure, revealing an expanded backdoor and a purpose-built SSH tunneling utility. Tortoiseshell is known for targeting IT providers and telecom companies, frequently through supply-chain attacks. The expanded toolset suggests the group is investing in stealthy persistence and covert network communications.
Cavern C2 Uses DNS and Google Apps Script to Blend Into Legitimate Traffic
Kaspersky details Iranian Cavern Manticore's expanded C2 framework using DNS and Google Apps Script, plus APT42's TAMECAT spyware in nuclear-sector phishing.
Kaspersky reported new components in the Cavern (Cav3rn) C2 framework, used by Iranian MOIS-affiliated Cavern Manticore (with overlaps to MuddyWater and OilRig's Lyceum) against Israeli entities, monitored since December 2025. The new GoogleService.dll module performs DNS A-record queries to choose between direct HTTPS and a Google Apps Script relay per transaction, with the DNS infrastructure able to rotate the Google deployment ID; Kaspersky also found an inter-component broker (rnp.dll) and linked the framework's plugin-based pivot to late April 2026. Separately, Group-IB and Kaspersky detailed HOLLOWGRAPH, a .NET NativeAOT DLL first seen in the wild June 7, 2026, that uses Microsoft 365 calendar events via the Graph API as two-way dead drops dated May 13, 2050, with DNS tunneling refreshing Entra ID credentials. DarkAtlas also reported APT42's TAMECAT modular surveillance framework delivered via LNK masquerading as PDFs in spear-phishing targeting the nuclear energy sector in April-May 2026, with the group using generative AI to accelerate operations.
North Korean Job Fraud Expands Beyond IT Into Healthcare and Sales
North Korea's IT worker scheme (Famous Chollima/PurpleDelta) has expanded from IT into healthcare, sales, and financial services roles worldwide.
Huntress and Recorded Future documented DPRK-linked fraudulent workers landing remote jobs beyond IT, including at an Australian healthcare company, a financial services firm, and a sales hire with a stolen identity. The scheme, tracked as Famous Chollima, Jasper Sleet, Nickel Tapestry, PurpleDelta, UNC5267, and Wagemole, uses forged identity documents, VPNs, proxies, and laptop farms with PiKVM and capture cards to fund Pyongyang's weapons programs. Recorded Future found the PurpleDelta cluster applied to 1,100+ companies between late 2024 and early 2025 with 22 fabricated personas, some AI-generated, using ChatGPT and AI transcription during interviews. Analysts assess the activity is ongoing and likely to expand in scale and sophistication.