W32/Agobot-EF is an IRC backdoor Trojan and network worm.
W32/Agobot-EF copies itself to network shares with weak passwords and attempts to spread to computers using the DCOM RPC and the RPC locator vulnerabilities.
These vulnerabilities allow the worm to execute its code on target computers with System level priviledges. For further information on these vulnerabilities and for details on how to protect/patch the computer against such attacks please see Microsoft security bulletins MS03-001 and MS03-026. MS03-026 has been superseded by Microsoft security bulletin MS03-039.
When first run W32/Agobot-EF copies itself to the Windows system folder with the filename explore.exe and creates the following registry entries so that the worm is run when Windows starts up:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\
Monitor = explor.exe
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices\
Monitor = explor.exe
W32/Agobot-EF also registers itself as a service which will be activated when Windows starts up. The name of the service is Monitor.
W32/Agobot-EF connects to a remote IRC server and joins a specific channel. The backdoor functionality of the worm can then be accessed by an attacker using the IRC network.
The worm also attempts to terminate and disable various security-related programs.