Trojan:Win64/Sirefef.D

Posted: November 7, 2011

Threat Metric

The Threat Meter is a malware assessment that SpywareRemove.com's research team is able to give every identifiable malware threat. Our Threat Meter includes several criteria based off of specific malware threats to value their severity, reach and volume. The Threat Meter is able to give you a numerical breakdown of each threat's initial Threat Level, Detection Count, Volume Count, Trend Path and Percentage Impact. The overall ranking of each threat in the Threat Meter is a basic breakdown of how all threats are ranked within our own extensive malware database. The scoring for each specific malware threat can be easily compared to other emerging threats to draw a contrast in its particular severity. The Threat Meter is a useful tool in the endeavor of seeking a solution to remove a threat or pursue additional analytical research for all types of computer users.

The following fields listed on the Threat Meter containing a specific value, are explained in detail below:

Threat Level: The threat level scale goes from 1 to 10 where 10 is the highest level of severity and 1 is the lowest level of severity. Each specific level is relative to the threat's consistent assessed behaviors collected from SpyHunter's risk assessment model.

Detection Count: The collective number of confirmed and suspected cases of a particular malware threat. The detection count is calculated from infected PCs retrieved from diagnostic and scan log reports generated by SpyHunter.

Volume Count: Similar to the detection count, the Volume Count is specifically based on the number of confirmed and suspected threats infecting systems on a daily basis. High volume counts usually represent a popular threat but may or may not have infected a large number of systems. High detection count threats could lay dormant and have a low volume count. Criteria for Volume Count is relative to a daily detection count.

Trend Path: The Trend Path, utilizing an up arrow, down arrow or equal symbol, represents the level of recent movement of a particular threat. Up arrows represent an increase, down arrows represent a decline and the equal symbol represent no change to a threat's recent movement.

% Impact (Last 7 Days): This demonstrates a 7-day period change in the frequency of a malware threat infecting PCs. The percentage impact correlates directly to the current Trend Path to determine a rise or decline in the percentage.

Threat Level:	9/10
Infected PCs:	9

First Seen:	November 7, 2011
Last Seen:	August 7, 2022
OS(es) Affected:	Windows

Trojan:Win64/Sirefef.D is a dropper Trojan that installs rootkits and rogue software like fake security programs and fake defraggers. Like other Trojans in the Trojan:Win64/Sirefef family, Trojan:Win64/Sirefef.D is designed to attack 64-bit Windows computers; 32-bit and Windows systems aren't threatened by Trojan:Win64/Sirefef.D, although they may be attacked by other Sirefef Trojans. SpywareRemove.com malware researchers note that removing Trojan:Win64/Sirefef.D can be difficult if not performed by adequately-powerful anti-malware products, since rootkits and other PC threats that can be installed by Trojan:Win64/Sirefef.D will take actions to shut down your PC security and anti-malware features.

Reasons to Keep Trojan:Win64/Sirefef.D at a Safe Distance from Your Hard Drive

As a Trojan, Trojan:Win64/Sirefef.D can be installed by several methods, but will always try to conceal its presence in some way. Trojan:Win64/Sirefef.D may be installed by drive-by-download scripts from hostile websites, be included in an installation package for an unrelated program or even be installed by another type of Trojan. Trojan:Win64/Sirefef.D itself is primarily-dedicated to installing a rootkit that launches automatically and hides its activities inside of normal Windows processes. You may be able to detect this activity by noting excessive RAM usage in Task Manager.

As a relative of both Trojan:Win64/Sirefef.E and Trojan:Win64/Sirefef.C, Trojan:Win64/Sirefef.D is also associated with rogue security products and other types of fake software. You may notice fake Microsoft Security Essentials pop-ups when Trojan:Win64/Sirefef.D is installing these programs, or other symptoms, including:

Fake system alerts and errors that announce that Windows is severely-damaged or that an essential program has been infected by a keylogger or other type of high-level PC threat.
Requests by unusual programs to purchase a registration or activation key.
Web browser hijacks that redirect your browser to a site that promotes malicious software.

Why You Don't Always Have to Worry About Trojan:Win64/Sirefef.D

Depending on its payload, Trojan:Win64/Sirefef.D's attacks may or may not be readily-visible to casual inspection. However, SpywareRemove.com malware experts always suggest that you use a competent anti-malware scanner to get rid of a Trojan:Win64/Sirefef.D infection and related PC threats, since anything less than this may allow Trojan:Win64/Sirefef.D or an even more-harmful infection to conduct attacks without being noticed. In most cases, appropriate methods of removing Trojan:Win64/Sirefef.D will insure that your PC doesn't suffer from any lingering harm after the fact.

As even brighter news than the above, some cases of Trojan:Win64/Sirefef.D detections can also be false positives. False positives are inaccurate Trojan:Win64/Sirefef.D alerts that cause no harm to your computer and can be ignored. In most situations, keeping your security software patched for the latest PC threat definitions will stop the appearance of Trojan:Win64/Sirefef.D false alerts. If your particular software fails to fix this Trojan:Win64/Sirefef.D warning quickly, in the meantime, you can set the program to ignore the supposedly 'infected' file without suffering any problems.

Technical Details

File System Modifications

Tutorials: If you wish to learn how to remove malware components manually, you can read the tutorials on how to find malware, kill unwanted processes, remove malicious DLLs and delete other harmful files. Always be sure to back up your PC before making any changes.

The following files were created in the system:

C:\Users\<username>\AppData\Local\b1a5d091\U\80000000.@

File name: 80000000.@
Size: 14.33 KB (14336 bytes)
MD5: 52e1c2499d79ae5b2d53a500b181f918
Detection count: 78
Mime Type: unknown/@
Path: C:\Users\<username>\AppData\Local\b1a5d091\U\80000000.@
Group: Malware file
Last Updated: August 7, 2022

C:\Qoobox\Quarantine\C\Users\<username>\AppData\Local\2aecbf38\U\80000000.@.vir

File name: 80000000.@.vir
Size: 17.4 KB (17408 bytes)
MD5: 22a3b4774f5941a67a42738bf7c3bf3e
Detection count: 77
Mime Type: unknown/vir
Path: C:\Qoobox\Quarantine\C\Users\<username>\AppData\Local\2aecbf38\U\80000000.@.vir
Group: Malware file
Last Updated: May 20, 2021

SYDLWB1083-1.zip

File name: SYDLWB1083-1.zip
Size: 61.5 KB (61507 bytes)
MD5: 2add59a56cc036b3dee806b1878a6d0e
Detection count: 75
Mime Type: unknown/zip
Group: Malware file
Last Updated: November 8, 2011

%AllUsersProfile%\Application Data\.dll

File name: %AllUsersProfile%\Application Data\.dll
File type: Dynamic link library
Mime Type: unknown/dll
Group: Malware file

%AllUsersProfile%\Application Data\.exe(looks like Trojan:win64/sirefef.D)

File name: %AllUsersProfile%\Application Data\.exe(looks like Trojan:win64/sirefef.D)
Mime Type: unknown/D)
Group: Malware file

More files

Registry Modifications

The following newly produced Registry Values are:

HKEY..\..\..\..{Subkeys}HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run ".exe"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run "Trojan:win64/sirefef.D"HKEY_CURRENT_USER\Software\Wow6432NodeHKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run "Trojan:win64/sirefef.D"