Sometimes we receive the following emails:


So, It's 100% a trojan horse packed by our demo version of ASProtect. You should check a process list using for example ProcessExplorer (it seems trojan blocks Windows Task Manager) and try to terminate unknown applications. If it closes a messagebox - it would be the 'bad' process. Try to find it on your disk and erase it. If you could describe a process of killing - we could describe it step by step for others.

Charles has sent us the following information:

http://www.sophos.com/security/analyses/w32agobotni.html

Description

This section helps you to understand how it behaves
W32/Agobot-NI is a backdoor Trojan and worm which spreads to computers
protected by weak passwords.

When first run, W32/Agobot-NI copies itself to the Windows system folder as
csrs.exe and creates the following registry entries to run itself on
startup:

HKLM\Software\Microsoft\Windows\CurrentVersion\Run\
Windows Update Service = csrs.exe

HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices\
Windows Update Service = csrs.exe

The Trojan runs continuously in the background providing backdoor access to
the computer.

The Trojan attempts to terminate and disable various anti-virus and security-
related programs and modifies the HOSTS file located at
%WINDOWS%\System32\Drivers\etc\HOSTS, mapping selected anti-virus
websites to the loopback address 127.0.0.1 in an attempt to prevent access to these sites. Typically the following mappings will be appended to the HOSTS file:

127.0.0.1 www.symantec.com
127.0.0.1 securityresponse.symantec.com
127.0.0.1 symantec.com
127.0.0.1 www.sophos.com
127.0.0.1 sophos.com
127.0.0.1 www.mcafee.com
127.0.0.1 mcafee.com
127.0.0.1 liveupdate.symantecliveupdate.com
127.0.0.1 www.viruslist.com
127.0.0.1 viruslist.com
127.0.0.1 viruslist.com
127.0.0.1 f-secure.com
127.0.0.1 www.f-secure.com
127.0.0.1 kaspersky.com
127.0.0.1 www.avp.com
127.0.0.1 www.kaspersky.com
127.0.0.1 avp.com
127.0.0.1 www.networkassociates.com
127.0.0.1 networkassociates.com
127.0.0.1 www.ca.com
127.0.0.1 ca.com
127.0.0.1 mast.mcafee.com
127.0.0.1 my-etrust.com
127.0.0.1 www.my-etrust.com
127.0.0.1 download.mcafee.com
127.0.0.1 dispatch.mcafee.com
127.0.0.1 secure.nai.com
127.0.0.1 nai.com
127.0.0.1 www.nai.com
127.0.0.1 update.symantec.com
127.0.0.1 updates.symantec.com
127.0.0.1 us.mcafee.com
127.0.0.1 liveupdate.symantec.com
127.0.0.1 customer.symantec.com
127.0.0.1 rads.mcafee.com
127.0.0.1 trendmicro.com
127.0.0.1 www.trendmicro.com

Recovery

Check your administrator passwords and review network security.

Replace the Hosts file from a backup or edit it in Notepad to remove the changes that the worm has made.

You will also need to edit the following registry entries, if they are present. Please read the warning about editing the registry.

At the taskbar, click Start|Run. Type 'Regedit' and press Return. The registry editor opens.

Before you edit the registry, you should make a backup. On the 'Registry' menu, click 'Export Registry File'. In the 'Export range' panel, click 'All', then save your registry as Backup.

Locate the HKEY_LOCAL_MACHINE entries:

HKLM\Software\Microsoft\Windows\CurrentVersion\Run\
Windows Update Service = csrs.exe

HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices\
Windows Update Service = csrs.exe

and delete them if they exist.

Close the registry editor.