Malware: Fighting Malicious Code

Malware Self-Preservation Techniques

We've discussed a variety of defensive techniques to fight viruses. However, the virus writers are aware of our defenses, and are actively working on undermining them. A malware specimen can employ several techniques in an attempt to avoid detection and elimination, including stealthing, polymorphism, metamorphism, and antivirus deactivation. Let's take a brief look at these self-preservation techniques one at a time.

Stealthing

Stealthing refers to the process of concealing the presence of malware on the infected system. As we discussed earlier in this chapter, a primitive stealthing method that is often used by companion viruses involves simply setting the “hidden” attribute of the virus file to make it ...