Win32/Lovgate is a family of mass-mailing worms that targets computers running certain versions of Microsoft Windows. The worm sends itself to e-mail addresses that it finds on the infected computer. The worm may also spread to writeable network shares. The worm has a backdoor component that allows attackers to remotely access and control the infected computer.

What to do now

To detect and remove this threat and other malicious software that may be installed on your computer, run a full-system scan with an appropriate, up-to-date, security solution. The following Microsoft products detect and remove this threat:

For more information on antivirus software, see

Threat behavior

When Win32/Lovgate runs, it copies itself to <system folder> with a file name such as winrpc.exe, syshelp.exe, winhelp.exe, or iexplore.exe. It modifies a registry key, which causes the worm to run each time Windows starts.
The worm spreads by sending itself as an e-mail attachment to addresses that it finds on the infected computer. It also spreads through writeable network shares by trying weak passwords. 
The worm drops a .dll file that acts as a backdoor to allow attackers to access the computer. Some variants also terminate security-related processes that are running on the computer.


There may be no readily apparent indications that your computer is infected by a variant of the Win32/Lovgate worm.


Take the following steps to help prevent infection on your computer:
  • Enable a firewall on your computer.
  • Get the latest computer updates for all your installed software.
  • Use up-to-date antivirus software.
  • Limit user privileges on the computer.
  • Use caution when opening attachments and accepting file transfers.
  • Use caution when clicking on links to webpages.
  • Avoid downloading pirated software.
  • Protect yourself against social engineering attacks.
  • Use strong passwords.
Enable a firewall on your computer

Use a third-party firewall product or turn on the Microsoft Windows Internet Connection Firewall.

Get the latest computer updates

Updates help protect your computer from viruses, worms, and other threats as they are discovered. It is important to install updates for all the software that is installed in your computer. These are usually available from vendor websites.

You can use the Automatic Updates feature in Windows to automatically download future Microsoft security updates while your computer is on and connected to the Internet.

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, such as Microsoft Security Essentials, that is updated with the latest signature files. For more information, see

Limit user privileges on the computer

Starting with Windows Vista and Windows 7, Microsoft introduced User Account Control (UAC), which, when enabled, allowed users to run with least user privileges. This scenario limits the possibility of attacks by malware and other threats that require administrative privileges to run.

You can configure UAC in your computer to meet your preferences:

Use caution when opening attachments and accepting file transfers

Exercise caution with email and attachments received from unknown sources, or received unexpectedly from known sources. Use extreme caution when accepting file transfers from known or unknown sources.

Use caution when clicking on links to webpages

Exercise caution with links to webpages that you receive from unknown sources, especially if the links are to a webpage that you are not familiar with, unsure of the destination of, or suspicious of. Malicious software may be installed in your computer simply by visiting a webpage with harmful content.

Avoid downloading pirated software

Threats may also be bundled with software and files that are available for download on various torrent sites. Downloading "cracked" or "pirated" software from these sites carries not only the risk of being infected with malware, but is also illegal. For more information, see 'The risks of obtaining and using pirated software'.

Protect yourself from social engineering attacks

While attackers may attempt to exploit vulnerabilities in hardware or software to compromise a computer, they also attempt to exploit vulnerabilities in human behavior to do the same. When an attacker attempts to take advantage of human behavior to persuade the affected user to perform an action of the attacker's choice, it is known as 'social engineering'. Essentially, social engineering is an attack against the human interface of the targeted computer. For more information, see 'What is social engineering?'.

Use strong passwords

Attackers may try to gain access to your Windows account by guessing your password. It is therefore important that you use a strong password – one that cannot be easily guessed by an attacker. A strong password is one that has at least eight characters, and combines letters, numbers, and symbols. For more information, see

Alert level: High
This entry was first published on: May 31, 2005
This entry was updated on: Aug 16, 2011

This threat is also detected as:
  • Win32/LovGate.A!Worm (CA)
  • W32.HLLW.Lovgate@mm (Symantec)
  • WORM_LOVGATE.A (Trend Micro)
  • W32/Lovgate.a@M (McAfee)