A recently exposed security vulnerability in Microsoft Defender SmartScreen has been utilized by an advanced persistent threat actor identified as Water Hydra, also known as DarkCasino. Their target: financial market traders. Trend Micro’s investigation unveiled the exploitation of CVE-2024-21412, a security loophole related to Internet Shortcut Files (.URL), marking the onset of a sophisticated campaign dating back to December 2023. This campaign involved bypassing Microsoft Defender SmartScreen using the vulnerability to introduce DarkMe malware into victims’ systems.
In this intricate attack chain, the threat actors utilized CVE-2024-21412 to circumvent Microsoft Defender SmartScreen’s defenses, ultimately infecting victims with the DarkMe malware. The cybersecurity firm’s analysis highlights the exploitation method, involving the deployment of a malicious installer file (“7z.msi”) through a booby-trapped URL (“fxbulls[.]ru”) masquerading as a harmless link to a stock chart image. This deceptive tactic aims to persuade victims to click on the link, initiating the infection process.
Despite the flaw being addressed by Microsoft in its February Patch Tuesday update, the success of the exploitation hinges on the threat actor’s ability to convince the victim to interact with the malicious file. The campaign’s modus operandi relies on the manipulation of user trust, enticing them to engage with seemingly innocuous content while concealing the true intentions of the attacker. By exploiting the CVE-2024-21412 vulnerability, the threat actors effectively sidestepped security protocols, underscoring the ongoing challenges in safeguarding against sophisticated cyber threats.
The ultimate objective of this intricate campaign is the surreptitious deployment of the DarkMe trojan, equipped with capabilities to execute additional commands, communicate with a command-and-control server, and harvest sensitive information from compromised systems. This incident underscores a concerning trend where cybercrime groups, armed with zero-day vulnerabilities, collaborate to launch highly sophisticated attacks. The convergence of technical expertise and malicious intent poses a formidable challenge for cybersecurity professionals and underscores the need for continued vigilance and robust defense mechanisms.
