Dynamic linker hijacking rootkit technology is a sophisticated malware technique that exploits the way an operating system loads shared libraries (dynamic link libraries, or DLLs) during program execution. The dynamic linker is responsible for resolving and loading these libraries when a program starts. By manipulating this process, attackers can redirect legitimate library calls to malicious versions, allowing them to execute arbitrary code with the privileges of the targeted process.
This rootkit technique often targets high-privilege processes, such as system services or security software, to maintain persistence and evade detection. The attacker places a malicious DLL in a directory that appears earlier in the library search path than the legitimate one, causing the dynamic linker to load the malicious version instead.
Example:
An attacker might target a system service like lsass.exe (Local Security Authority Subsystem Service) on Windows. By placing a malicious DLL in a directory that the dynamic linker checks before the legitimate library location, the attacker can intercept sensitive operations, such as credential handling, and exfiltrate data.
In cloud environments, such as those protected by Tencent Cloud, measures like Tencent Cloud Host Security (CWP) can detect and mitigate such threats by monitoring file integrity, analyzing process behavior, and blocking unauthorized library injections. Additionally, Tencent Cloud Security Center provides real-time threat detection and response to safeguard against advanced rootkit techniques.