Windows Defender detects and removes this threat.

This trojan is a 64-bit component of Win32/Sirefef - a family of malware that uses stealth to hide its presence on your computer. Trojans in this family can do different things, including:

• Downloading and running other files
• Contacting remote hosts
• Disabling security features

Members of the family can also change search results, which can generate money for the attackers who use Sirefef.

Windows Defender detects and removes this threat.

See the Win32/Sirefef family description for more information.

Windows Defender detects and removes this threat.

See the Win32/Sirefef family description for more information.

Microsoft security software detects and removes this threat.

This family of malware uses stealth to hide its presence on your PC. Trojans in this family can do different things, including:

• Downloading and running other files
• Contacting remote hosts
• Disabling security features

Members of the family can also change search results, which can generate money for the hackers who use Sirefef.

Variants of Win32/Sirefef might be installed by other malware, including variants of the Trojan:Win32/Necurs family.

Find out ways that malware can get on your PC.

Windows Defender detects and removes this threat.

Windows Defender detects and removes this threat.

Trojan:Win64/Sirefef.W is the 64-bit user-mode component of Win32/Sirefef - a multi-component family of malware that moderates your Internet experience by modifying search results, and generating pay-per-click advertising revenue for its controllers. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components or performing a payload.

Trojan:Win64/Sirefef.AE is a component of Win64/Sirefef - a multi-component family of malware that uses stealth to hide its presence on your computer. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components, or performing the payload.

Note: This Sirefef variant has been observed using specific ports for its peer-to-peer communications. We strongly encourage you to block access to the following ports to limit Sirefef’s communication channels and prevent additional Sirefef components being downloaded:

• 16464
• 16465
• 16470
• 16471

You can read more about how to block access to a port in this article: http://support.microsoft.com/kb/813878

Trojan:Win64/Sirefef.AF is a component of Win64/Sirefef - a multi-component family of malware that uses stealth to hide its presence on your computer. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components, or performing the payload.

Note: This Sirefef variant has been observed using specific ports for its peer-to-peer communications. We strongly encourage you to block access to the following ports to limit Sirefef’s communication channels and prevent additional Sirefef components being downloaded:

• 16464
• 16465
• 16470
• 16471

You can read more about how to block access to a port in this article: http://support.microsoft.com/kb/813878

Trojan:Win64/Sirefef.AI is a component of Win64/Sirefef - a multi-component family of malware that uses stealth to hide its presence on your computer. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components, or performing the payload.

Note: This Sirefef variant has been observed using specific ports for its peer-to-peer communications. We strongly encourage you to block access to the following ports to limit Sirefef’s communication channels and prevent additional Sirefef components being downloaded:

• 16464
• 16465
• 16470
• 16471

You can read more about how to block access to a port in this article: http://support.microsoft.com/kb/813878

Trojan:Win64/Sirefef.AB is a component of the Sirefef multi-platform rootkit, related to Win32/Sirefef. Sirefef is multi-component malware family that modifies search results when you search for something on the Internet and generates pay-per-click advertising revenue for its controllers. This particular component clicks on links supplied by a remote attacker to generate revenue.

Trojan:Win64/Sirefef.M is the 64-bit user-mode component of Win32/Sirefef - a multi-component family of malware that moderates your Internet experience by changing search results and generating pay-per-click advertising revenue for its controllers. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components, or performing a payload.

Windows Defender detects and removes this threat.

It is a user-mode component of Win32/Sirefef - a multi-component family of malware that meddles with your Internet experience by changing search results and generating pay-per-click advertising revenue for its controllers. The family consists of multiple parts that do different functions, like downloading updates and additional components, hiding existing components, or doing a payload.

Trojan:Win64/Sirefef.U is a component of Win64/Sirefef - a multi-component family of malware that moderates your Internet experience by changing search results and generating pay-per-click advertising revenue for its controllers. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components, or performing a payload.

Trojan:Win64/Sirefef.Q is 64-bit user mode component of Win32/Sirefef - a multi-component family of malware that moderates your Internet experience by changing search results and generating pay-per-click advertising revenue for its controllers. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components, or performing a payload.

Trojan:Win64/Sirefef.Y is a component of Win32/Sirefef - a multi-component family of malware that moderates your Internet experience by changing search results and generating pay-per-click advertising revenue for its controllers. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components, or performing a payload.

Trojan:Win64/Sirefef.D is the 64-bit user-mode component of Win32/Sirefef - a multi-component family of malware that moderates your Internet experience by changing search results and generating pay-per-click advertising revenue for its controllers. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components, or performing a payload.

Trojan:Win64/Sirefef.E is the 64-bit user-mode component of Win32/Sirefef - a multi-component family of malware that moderates your Internet experience by changing search results and generating pay-per-click advertising revenue for its controllers. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components, or performing a payload.

Trojan:Win64/Sirefef.J is a component of Win32/Sirefef - a multi-component family of malware that moderates your Internet experience by changing search results and generating pay-per-click advertising revenue for its controllers. The family consists of multiple parts that perform different functions, such as downloading updates and additional components, hiding existing components, or performing a payload.

Trojan:Win64/Sirefef.B is a trojan that connects to a remote server to download arbitrary files which can include malware, such as other components of Sirefef, and may be present on an affected computer as a file named "consrv.dll".