Threat behavior
TrojanDownloader:Win32/Small.AON is a trojan that downloads and runs files on impacted systems. TrojanDownloader:Win32/Small.AON also terminates security related processes and processes that ma be related to competing malicious software. Processes that may be terminated by TrojanDownloader:Win32/Small.AON include the following:
_avpcc.exe
_avpm.exe
anti-trojan.exe
antivirus.exe
atcon.exe
atguard.exe
atguard.exe
atupdater.exe
aupdate.exe
autodown.exe
auto-protect
avgnt.exe
avguard.exe
avp.exe
avp32.exe
avpcc.exe
avpm.exe
avwupsrv.exe
bidef.exe
bidserver.exe
bipcp.exe
bipcpevalsetup.exe
blackice.exe
claw95.exe
claw95cf.exe
claw95cf.exe
clean.exe
defscangui.exe
defwatch.exe
drweb32.exe
f-agnt95.exe
firewall.exe
flowprotector.exe
frw.exe
kavlite40eng.exe
kavpers40eng.exe
kavpf.exe
kerio-pf-213-en-win.exe
kerio-wrl-421-en-win.exe
kerio-wrp-421-en-win.exe
monitor.exe
nav
nav.exe
nav80try.exe
navap
navap.exe
navapsvc.exe
navapsvc.exe
navapw32.exe
navdx.exe
navengnavex15
navengnavex15.exe
navlu32.exe
navstub.exe
navw32.exe
navwnt.exe
netarmor.exe
netstat.exe
netutils.exe
norton_internet_secu_3.0_407.exe
nprotect.exe
nwservice.exe
nwtool16.exe
ostronet.exe
outpostinstall.exe
outpostproinstall.exe
pcfwallicon.exe
pcfwallicon.exe
persfw.exe
perswf.exe
pfwadmin.exe
safeweb.exe
sofi.exe
taskmon.exe
vpfw30s.exe
vptray.exe
webtrap.exe
zapro.exe
zapsetup3001.exe
zatutor.exe
zauinst.exe
zonalm2601.exe
zonealarm.exe
Prevention
Take the following steps to help prevent infection on your system:
Enable a firewall on your computer.
Get the latest computer updates.
Use up-to-date antivirus software.
Use caution with attachments and file transfers.
Enable a firewall on your computer
Use a third-party firewall product or turn on the Microsoft Windows XP Internet Connection Firewall.
To turn on the Internet Connection Firewall in Windows XP
Click Start, and click Control Panel.
Click Network and Internet Connections. If you do not see Network and Internet Connections, click Switch to Category View.
Click Change Windows Firewall Settings.
Select On.
Click OK.
Get the latest computer updates
Updates help protect your computer from viruses, worms, and other threats as they are discovered. You can use the Automatic Updates feature in Windows XP to automatically download future Microsoft security updates while your computer is on and connected to the Internet.
To turn on Automatic Updates in Windows XP
Click Start, and click Control Panel.
Click System.
Click Automatic Updates.
Select a setting. Microsoft recommends selecting Automatic. If you do not choose Automatic, but you choose to be notified when updates are ready, a notification balloon appears when new downloads are available to install. Click the notification balloon to review and install the updates.
Use up-to-date antivirus software
Most antivirus software can detect and prevent infection by known malicious software. To help protect you from infection, you should always run antivirus software that is updated with the latest signature files. Antivirus software is available from several sources. For more information, see http://www.microsoft.com/athome/security/downloads/default.mspx
Use caution with attachments and file transfers
Exercise caution with e-mail and attachments received from unknown sources, or received unexpectedly from known sources. Use extreme caution when accepting file transfers from known or unknown sources.
