spoofing

Short definition from Wiktionary

Verb

1. 1
   present participle and gerund of spoof

Noun

1. 1
   Falsifying one's identity or other identifying information (e.g. location) by technical means to deceive or gain access.
2. 2
   A method of attacking a computer program, in which the program is modified so as to appear to be working normally when in reality it has been modified with the purpose of circumventing security mechanisms.
3. 3
   Phishing.