Cockroach
A more subtle version of Gremlins, Cockroach has the same effects sans the random program requests, and it eats files instead of programs. Useless in Netrun combat, Cockroach sneakily multiplies, eating one file per 24-hour period per three cockroaches (rounded up). For instance, Day 1 the first cockroach eats one file, making another cockroach. Days 2 and 3 the same thing occurs; there are now four cockroaches. Day 4 files are turned into cockroaches, Day 5 two more files are turned into cockroaches, and so on in 10 days 35 files have been turned into cockroaches! The sysop will have to purge the entire system, looking for and destroying all the cockroaches, or they'll just start taking over again.
Options: Pseudo-intellect, Movement, Recognition