Cybersecurity firm Intezer reveals the emergence of SSLoad malware distributed via PhantomLoader, a previously undocumented loader. Researchers Nicole Fishbein and Ryan Robinson detail how PhantomLoader is embedded into legitimate DLLs, like EDR or AV products, using self-modifying techniques to evade detection. SSLoad, likely offered under a Malware-as-a-Service model, infiltrates systems through phishing emails and deploys additional malware.
Prior reports from Palo Alto Networks Unit 42 and Securonix highlight SSLoad’s usage in deploying Cobalt Strike, a legitimate adversary simulation software, since April 2024. The attack chain typically involves an MSI installer initiating PhantomLoader execution, masquerading as an antivirus DLL. Once activated, the Rust-based downloader DLL retrieves the main SSLoad payload from a remote server, facilitating system compromise.
SSLoad’s final payload, also Rust-based, fingerprints the compromised system and communicates with a command-and-control server. This sophisticated malware exhibits dynamic string decryption and anti-debugging measures, emphasizing its adaptability and complexity. It demonstrates the capability to gather reconnaissance and deploy further payloads through various delivery methods, illustrating the evolving tactics employed by cybercriminals.
These developments coincide with observed phishing campaigns disseminating remote access trojans like JScript RAT and Remcos RAT, enhancing cybercriminals’ capabilities for persistent operation and executing commands remotely. As SSLoad continues to evolve, cybersecurity measures must adapt to counter emerging threats and safeguard against potential breaches.
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