Iranian Hackers Attack Dropbox
Security researchers have discovered a new cyber espionage campaign directed against the aerospace and telecommunications industries, primarily in the Middle East. These attacks seem to have the purpose of stealing sensitive information about critical assets, organisations’ infrastructure and technology while remaining in the dark and successfully evading security solutions.
A group of hackers believed to be based in Iran is targeting organisations also in the US and elsewhere with a campaign that uses cloud storage service Dropbox. The group's main malware tool is a remote access Trojan (RAT) called ShellClient that has been in development and likely active use since 2018, as different versions with functionality improvements have been identified.
The leading US cyber security company Cybereason has investigated the attacks which they call "Operation Ghostshell," pointing out the use of a previously undocumented and stealthy remote access trojan (RAT) called ShellClient that's deployed as the main spy tool of choice.
The first sign of the attacks was observed in July 2021 against a handpicked set of victims, indicating a highly targeted approach. "The ShellClient RAT has been under ongoing development since at least 2018, with several iterations that introduced new functionalities, while it evaded antivirus tools and managed to remain undetected and publicly unknown," Cybereason researchers reported.
Cybereason traced the roots of this threat back to November 6, 2018, previously operating as a standalone reverse shell before evolving to a sophisticated backdoor, highlighting that the malware has been under continuous development with new features and capabilities added by its authors.
What's more, the adversary behind the attacks is also said to have deployed an unknown executable named "lsa.exe" to perform credential dumping. Investigation into the attribution of the cyber attacks has also yielded an entirely new Iranian threat actor named MalKamak that has been operating since around the same time period and has eluded discovery and analysis thus far.
These hackers have possible connections to other Iranian state-sponsored APT threat actors such as Chafer APT and Agrius APT. Indeed, Agrius APT was found posing as a ransomware operation in an effort to conceal the origin of a series of data-wiping hacks against Israeli targets.
The Dropbox storage contains three folders, each storing information about the infected machines, the commands to be executed by the ShellClient RAT, and the results of those commands. "Every two seconds, the victim machine checks the commands folder, retrieves files that represent commands, parses their content, then deletes them from the remote folder and enables them for execution," the researchers said.
Cybereason: Bloomberg: The Hacker News: TechTarget: Information Security Buzz:
CSO Online: Haktechs: CyberSocialHub:
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