Malicious Software Encyclopedia: Win32/Bagz
Published:
August 9, 2005
Win32/Bagz is a family of mass-mailing worms that targets certain versions of Microsoft Windows. The worm spreads as an e-mail attachment and runs when the user opens the attachment. It can download and run other malicious files from a server.
On This Page
Threat Overview
| Class/type | Worm - Mass Mailer
|
| Discovered | October 5, 2004 |
| Circulating | Yes |
| Affected operating systems | Windows NT 4.0
Windows 95
Windows 2000
Windows XP
Windows Server 2003
|
| Affected software |
Not specified
|
| Infection rating | Medium |
| Recovery difficulty | Moderate |
| Damage rating | Medium |
| Transmission rating | Medium |
Aliases (Also Known As)
Different antivirus vendors may be using different names to refer to this malicious software. Here are some of the names currently in use by antivirus software vendors participating in the Microsoft Virus Information Alliance (VIA):
McAfee:
W32/Bagz.gen@MMSymantec:
W32.Bagz@mmTrend Micro:
WORM_BAGZ.GEN
Learn more about the
Microsoft Virus Information Alliance.
Technical Analysis
When Win32/Bagz runs, it can take the following actions:
Copy itself as a new file to <system folder> with a name such as tutorial.doc<multiple spaces>.exe or sqlssl.doc<multiple spaces>.exe.
Drop other files in <system folder> for various purposes. Examples include the following:
dl.exe, a component that can download other files from a server and run them.
syslogon.exe, a component for mass mailing.
tutorial.zip, an archive file used by the worm as an e-mail attachment. This file contains the executable file tutorial.doc<multiple spaces>.exe.
ipdb.dll and jobdb.dll, files used by the worm to store information such as IP addresses, e-mail addresses, and e-mail server information that the worm gathers from the infected computer.
Cause itself to run automatically each time Windows starts, as in the following ways:
Disable security-related programs, as in the following ways:
Disable the Windows firewall by running a command-line script.
Install its own network driver to bypass other local firewalls.
Overwrite the Windows system hosts file, <system folder>\drivers\etc\hosts, to prevent access to security-related Web sites.
Terminate processes and delete files and registry entries.
Send a copy of itself as an e-mail attachment to addresses found on the infected computer. The e-mail sender is spoofed. The subject line and message body vary. The attachment may have a .zip extension or a double extension that is partly hidden to make it appear that opening the attachment is safe.
How to Prevent Infection
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 unknown attachments.
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, and click Network Connections. If you do not see Network and Internet Connections, click Switch to Category View.
Highlight a connection that you want to help protect, and click Change settings of this connection.
Click Advanced, and select Protect my computer and network by limiting or preventing access to this computer from the Internet.
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 Microsoft 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 Performance and Maintenance. If you do not see Performance and Maintenance, click Switch to Category View.
Click System.
Click Automatic Updates, and select Keep my computer up to date.
Select a setting. Microsoft recommends selecting Automatically download the updates, and install them on the schedule that I specify and setting a regular update time.
If you choose to have Automatic Updates notify you in step 5, you will see a notification balloon when new downloads are available to install. Click the notification balloon to review and install updates.
Use up-to-date antivirus software
Most antivirus software can detect and prevent infection by known malicious software. You should always run antivirus software on your computer that is updated with the latest signature files to automatically help protect you from infection.
Use caution with unknown attachments
Use caution before opening unknown e-mail or IM attachments, even if you know the sender. If you cannot confirm with the sender that a message is valid and that an attachment is safe, delete the message immediately, and run up-to-date antivirus software to check your computer for viruses.
How to Tell If Your Computer Is Infected
There may be no readily apparent indications that your computer is infected by Win32/Bagz. However, your computer may be infected by this worm if you detect any of the following symptoms:
- The Windows firewall is disabled.
- Other local firewalls are disabled.
- Some security-related programs do not run normally.
- The Windows system hosts file, <system folder>\drivers\etc\hosts, has been changed. This may block access to security-related Web sites.
- Files such as the following are present in the Windows system folder:
tutorial.doc<multiple spaces>.exe
sqlssl.doc<multiple spaces>.exe
dl.exe
run32.exe
syslongon.exe
sysinfo32.exe
ipdb.dll
jobdb.dll
wdate.dll
tutorial.zip
ndisrd.sys
ndisapi.dll
<system folder>\drivers\ndisrd.sys
How to Recover from Infection
Automatic Recovery
To attempt to automatically remove this threat, run one of the following removal tools:
Transmission Methods
| Method | Description |
|---|
| Social Engineering | Uses the e-mail message text to prompt the user to open the attachment. |
| Mass Mailer | Sends itself as an e-mail attachment to e-mail addresses on the infected computer. |
Payload Information
| Payload type | Trigger | Description |
|---|
| Compromises Security | Execution | Disables security-related applications. Downloads and runs other malicious files from a server. |
| Creates files | Execution | Copies itself to the Windows system folder and drops other files there. |
