Microsoft security software detects and removes this threat.

This threat is a member of the Win32/Sefnit family. This family can hide on your PC and do different things, including:

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

They can also change your search results, which can generate money for malicious hackers.

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

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.

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 attackers who use Sirefef.

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

For more information, please see the Win32/Sirefef family description.

Trojan:Win32/Sirefef.O is a trojan component of the Win32/Sirefef family, and is installed by variants of TrojanDropper:Win32/Sirefef. The trojan provides functionality for other installed Win32/Sirefef rootkit components.

Trojan:Win32/Sirefef.BC 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.

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

Microsoft security software detects and removes this threat.

This family of malware uses stealth to hide itself. 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.

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

See the Win32/Sirefef family description for more information.

Windows Defender Antivirus detects and removes this threat.

 

This threat is a member of the Win32/Sirefef family of trojans. It can allow a hacker to perform a number of actions on your PC.

Microsoft security software detects and removes this threat.

This threat is a member of the Win32/Sirefef family of malware. 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 may be installed by other malware, including variants of the Trojan:Win32/Necurs family.

There is moe information on this type of threat in the Win32/Sirefef family description.

Trojan:Win32/Sirefef.CI is a malicious program that is unable to spread of its own accord. It may perform a number of actions of an attacker's choice on an affected computer.

Trojan:Win32/Sirefef.AC 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.