Xtac stays resident in memory and infects COM and EXE files when they are executed. COMMAND.COM is infected by overwriting an unused area.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
Sometimes the virus deletes files with the following extensions:
Xtac contains the following unencrypted internal text:
good news! you have justbeen smitten by XTAC - lyndon siao, usc-tc
Xtac was reported to be in the wild in the USA in January 1996.