Malicious Software Encyclopedia: Win32/Spybot
Published:
June 14, 2005
Win32/Spybot is a network worm that targets certain versions of Microsoft Windows. The worm can spread through writeable network shares that have weak administrator passwords, or through peer-to-peer, file-sharing programs. It can also spread by exploiting various Windows vulnerabilities. Win32/Spybot also has a backdoor component that allows attackers to control an infected computer.
On This Page
Threat Overview
| Class/type | Worm - Network
|
| Discovered | August 31, 2004 |
| Circulating | Yes |
| Affected operating systems | Windows NT 3.x
Windows NT 4.0
Windows 95
Windows 2000
Windows XP
|
| Affected software |
Not specified
|
| Infection rating | Low |
| Recovery difficulty | Moderate |
| Damage rating | Medium |
| Transmission rating | Medium |
Related Security Bulletins
The following Microsoft Security bulletins are related to this issue:
MS03-026 - Buffer Overrun In RPC Interface Could Allow Code Execution (823980)MS04-011 - Security Update for Microsoft Windows (835732)Technical Analysis
When a Win32/Spybot worm runs, it may take the following actions:
Copy itself to one or more of the following locations:
%windir% or <system folder>. It can modify registry keys or add a Windows service, which causes the Trojan to run when Windows starts.
Writeable network shares at random IP addresses. After copying itself, the worm creates a task on the remote computer to run itself there.
The share folder of a file-sharing application. The worm uses a misleading file name that might cause a user on another computer to download and run the worm inadvertently.
Exploit one or more of eight Windows vulnerabilities that allow it to copy and run itself on a remote computer. For example, the worm can exploit the Windows vulnerability that allows an attacker to create a shell on the remote computer.
- Connect to an IRC server and channel to open a backdoor, which allows unauthorized access to the infected computer. The backdoor allows an attacker to perform operations such as the following:
- Retrieve system information such as CPU speed, memory usage, Windows operating system, connection type, IP address, and Windows logon information.
- Send e-mail to other attackers.
- Start denial of service (DoS) attacks.
- Download and run files.
- Delete network shares.
- Redirect connections.
- Enable DCOM protocol.
- Scan for computers with weak administrator passwords.
- Scan ports.
- Set up a TFTP server or an HTTPD server.
- Log keystrokes.
- Gather CD keys of various games.
- List or terminate certain processes and services.
- Remove the worm.
How to Prevent Infection
Follow these steps to prevent infection from Win32/Spybot:
Enable a firewall on your computer.
Get the latest computer updates.
Use up-to-date antivirus software.
Use strong passwords.
Remove unneeded network shares.
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. If you don't have antivirus software installed, you can get it from one of several companies. For more information, see http://www.microsoft.com/athome/security/downloads/default.mspx
Use strong passwords
A strong password has at least eight characters and includes a combination of letters, numbers, and symbols. It is easy for you to remember, but difficult for others to guess. Weak passwords include any words in the dictionary, names, dates, consecutive letters or numbers, common words with symbol substitutions (for example, p@ssw0rd), and so on.
Remove unneeded network shares
Malicious software can often spread over network shares. Remove unneeded network shares that are mapped to your computer.
To remove network shares in Windows XP
On the Start menu, click My Computer.
On the Tools menu, click Disconnect Network Drives…
In the Disconnect Network Drives dialog box, click the drives to disconnect and click OK.
How to Tell If Your Computer Is Infected
There are no readily apparent indications that your computer is infected with Win32/Spybot.
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 |
|---|
| Network Shares | Can copy itself to writeable network shares at random IP addresses using weak administrator passwords. |
| Exploits Vulnerability | Can exploit one or more of eight Windows vulnerabilities that allow the worm to copy and run itself on a remote computer. |
| Infected Files | Can copy itself to the share folder of a file-sharing application on a remote computer. |
Payload Information
| Payload type | Trigger | Description |
|---|
| Release information | Execution | Releases information to attackers. |
| Compromises Security | Execution | Allows an attacker to perform operations on the computer. |
| Creates files | Execution | Copies itself to %windir% or <system folder>. |
Affected Ports
| Protocol | Port number |
|---|
| TCP | 445 |
| TCP | 135 |
