Cloaking
When referring to computing, cloaking in general refers to the technique of hiding something or giving a false appearance. For example, with IP cloaking a website can disguise itself as something else to a search engine, but look completely different to a normal visitor. Cloaking is also how most malware infects a computer; for example, malware may disguise itself as an antivirus program when in reality it is a virus or other scareware.
Also see: Security definitions, Spoof, Trojan horse