Hunters International, a notorious ransomware group, has recently deployed a new remote access trojan (RAT) known as SharpRhino to target IT professionals and infiltrate corporate networks. Discovered by Quorum Cyber researchers, SharpRhino is distributed through a typosquatting website that masquerades as the legitimate Angry IP Scanner, a tool commonly used by IT experts. The malware is delivered as a digitally signed installer named ‘ipscan-3.9.1-setup.exe,’ which contains a self-extracting, password-protected 7z archive loaded with files necessary for the infection.
Once installed, SharpRhino enables Hunters International to achieve initial infection, elevate privileges on compromised systems, and deploy ransomware payloads. The malware modifies the Windows registry for persistence and creates directories for command and control (C2) communication. SharpRhino uses PowerShell scripts to execute various commands stealthily, demonstrating its capabilities by executing benign actions like launching the Windows calculator as part of its tests.
Launched in late 2023, Hunters International has rapidly gained notoriety, with 134 ransomware attacks reported in 2024 alone. The group has targeted high-profile organizations, including U.S. Navy contractor Austal USA and Japanese optics giant Hoya, showcasing its capability to breach significant entities. This latest SharpRhino RAT highlights the group’s evolving tactics and their focus on IT professionals who may have elevated access privileges.
To mitigate the risk posed by such threats, IT professionals are advised to be cautious of typosquatting sites and malvertising, use ad blockers, and download software only from official project sites. Implementing a comprehensive backup strategy, performing network segmentation, and keeping all software up to date are essential measures to reduce the impact of ransomware attacks and prevent privilege escalation and lateral movement within networks.
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