Troj/Ranck-AH is a proxy Trojan that allows a remote intruder to route HTTP traffic through the computer.
Troj/Ranck-AH sets an entry in the registry at the following location so as to run itself on system startup:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run\
ICQMsn = <path to self>
Troj/Ranck-AH runs continuously in the background listening on a port.