Threat actors exploit HijackLoader because it is a powerful tool for injecting malicious code into legitimate processes, enabling stealthy execution of payloads.
This technique helps them to evade detection by leveraging trusted applications to carry out malicious activities.
This scenario makes it more complicated for security measures to effectively identify and mitigate the threat.
Cybersecurity researchers at Crowdsrtike recently discovered a HijackLoader (aka IDAT Loader) that employs sophisticated techniques to evade detection.
Sophisticated HijackLoader Malware
CrowdStrike researchers found HijackLoader evolving with new defense evasion tricks like process hollowing, pipe-triggered activation, and a mix of process doppelganging.
These enhancements make it stealthier and harder to analyze, not only that even extra unhooking techniques were also spotted.
CrowdStrike uncovered a sophisticated HijackLoader sample that starts with streaming_client.exe, which obfuscates a configuration to evade static analysis.
Using WinHTTP APIs, it tests internet connectivity by contacting https[:]//nginx[.]org. If successful, it downloads a second-stage config from a remote server.
After getting the second-stage config, the malware hunts for PNG header bytes and a magic value. It then decrypts using XOR and decompresses using RtlDecompressBuffer API.
Next, it loads a legit Windows DLL specified in the configuration and writes the shellcode to its .text section for execution. It utilizes Heaven’s Gate to evade user mode hooks and injects more shellcodes into cmd.exe.
The third-stage shellcode injects a final payload like a Cobalt Strike beacon into logagent.exe using process hollowing.
HijackLoader evades detection with Heaven’s Gate hook bypass and unhooking DLLs watched by security tools. It also uses process hollowing variations and transacted hollowing for injection.
This merges the transacted section and process doppelgänging with DLL hollowing.
Main Evasion Techniques
Here below, we have mentioned all the main evasion techniques that the HijackLoader and Shellcode use:-
- Hook Bypass: Heaven’s Gate and Unhooking
- Process Hollowing Variation
- Interactive Process Hollowing Variation: Tradecraft Analysis
- Transacted Hollowing² (Transacted Section/Doppelgänger + Hollowing)
- Transacted Section Hollowing
- Process Hollowing
The exploitation of HijackLoader underscores the significance of proactive cybersecurity measures to detect and prevent such covert attacks.
Organizations should prioritize regular security audits, employ robust endpoint protection, and stay updated on emerging threats to effectively defend against the evolving tactics employed by threat actors.
Besides this, user education and awareness training are essential in mitigating the risks associated with these sophisticated attack vectors.
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