AngryBoy is not a dangerous memory resident encrypted parasitic virus. It copies itself to the High Memory Area, hooks INT 21h and writes itself to the end of EXE files that are executed. While infecting the virus uses undocumented DOS system formats and fools anti-virus behavior blockers. Depending on the system timer the virus displays a message in Russian.
The virus contains the text string:
Still Alive virus. (c) Angry Boy, Vitebsk, 1998
Securelist (Kaspersky Labs), Virus.DOS.AngryBoy.2132