IAT Hooking: Integrity Detection and Triage
An IAT entry normally points to an imported routine. Redirecting it can support testing and legitimate instrumentation, or it can be evidence of in-memory tampering. Investigation needs a trusted baseline and cross-source evidence.
Integrity findings require context
A changed IAT entry is not sufficient to attribute maliciousness. Endpoint security products, compatibility tooling, debuggers, and approved application instrumentation can alter normal execution. Validate the loaded module, signer, memory protections, OS version, process role, and product inventory before escalating.
Safe analyst setup
Use an authorized lab and baseline expected modules with Process Explorer. Acquire memory only under an approved process and analyze it with Volatility 3. Compare findings with EDR image-load, process, and network events; preserve evidence before remediation.
Controls and CVE context
Enable EDR tamper protection, code integrity, application control, and least privilege. CVE-2022-21882 was a Windows Win32k elevation-of-privilege vulnerability exploited in the wild, showing why untrusted in-process code and unpatched privilege boundaries amplify each other. Patch and investigate unexpected integrity changes quickly.
Key takeaways
- IAT changes can be benign or suspicious; a baseline is essential.
- Validate module trust, memory state, and runtime behavior together.
- Use endpoint integrity controls and keep privilege-boundary patches current.