Trojan:Win32/Sirefef.AC

Posted: April 10, 2012

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.

Ranking:	697
Threat Level:	2/10
Infected PCs:	168,395

First Seen:	April 10, 2012
Last Seen:	October 17, 2023
OS(es) Affected:	Windows

Trojan:Win32/Sirefef.AC is a malicious .exe file that's used as one part of a multi-component ZeroAccess Rootkit (AKA Sirefef Trojan) infection. Because Trojan:Win32/Sirefef.AC is never installed by itself and will always serve as a portent of the presence of other PC threats, what is recommended by SpywareRemove.com malware researchers is to run a scan of your entire PC thoroughly to detect and remove both Trojan:Win32/Sirefef.AC and any related malicious software that's been installed without your permission. Trojan:Win32/Sirefef.AC doesn't display visible symptoms of its attacks and, like other rootkit-based PC threats, may restore itself from incomplete deletion or a System Restore rollback. However, you may be able to detect Trojan:Win32/Sirefef.AC indirectly by noting some of the symptoms of a ZeroAccess Rootkit's payload, such as browser redirects and unusual search engine results. Despite the low visibility of its presence and hostile behavior, Trojan:Win32/Sirefef.AC should always be considered a threat to your machine that should be removed immediately, like all rootkits.

Trojan:Win32/Sirefef.AC: a Piece of the Puzzle That Confounds Your Online Searches

By itself, Trojan:Win32/Sirefef.AC doesn't have significant symptoms, and its 5.5k file size causes Trojan:Win32/Sirefef.AC to be easy to overlook unless you're specifically searching for Trojan:Win32/Sirefef.AC on your PC. SpywareRemove.com malware researchers recommend that you use appropriate security programs to detect Trojan:Win32/Sirefef.AC, which will always be installed with other PC threats from the Sirefef family, such as Win32/Sirefef.AH, TrojanDropper:Win32/Sirefef, Trojan:Win32/Sirefef.S, Trojan:Win32/Sirefef.J, Trojan:Win64/Sirefef.K or Virus:Win32/Sirefef.N. Depending on the type of anti-malware software that you use to find Trojan:Win32/Sirefef.AC, Trojan:Win32/Sirefef.AC may also be detected under one of various aliases, such as Troj/ZAccess-AH, W32/Troj_Generic.UUZF and Trojan.Zeroaccess!inf.

Symptoms of an overall Sirefef infection can be observed in the form of browser hijacks, especially redirect attacks that reroute your searches through questionable search engine websites as a form of click fraud. Since these attacks are accomplished by way of Trojan:Win32/Sirefef.AC and other Sirefef components, as well as various system setting changes, SpywareRemove.com malware researchers warn against any attempt to stop them simply by changing your browser or browser settings.

Why Trojan:Win32/Sirefef.AC, Like a Bad Memory, Keeps Coming Back

If Trojan:Win32/Sirefef.AC is deleted incompletely or you fail to remove all related PC threats along with Trojan:Win32/Sirefef.AC, Trojan:Win32/Sirefef.AC will most likely be reinstalled the next time your PC reboots. SpywareRemove.com malware researchers also note that this especially includes attempts to delete Trojan:Win32/Sirefef.AC with Windows functions such as System Restore, which are ineffective at removing all components of most rootkit infections like ZeroAccess. However, as a silver lining, Trojan:Win32/Sirefef.AC and its kin are Windows-specific, and as such, are unable to attack other types of operating systems.

Trojan:Win32/Sirefef.AC was identified by many PC security companies in early February of 2012. To insure that your security software can find and remove Trojan:Win32/Sirefef.AC completely, SpywareRemove.com malware experts reinforce that it is crucial to have your software updated to at least that point (and, preferentially, to the latest available threat definitions patch). You may also need to take further steps to disable Trojan:Win32/Sirefef.AC and associated malicious software before Trojan:Win32/Sirefef.AC can be fully deleted.

Technical Details

Additional Information

The following URL's were detected:

mykiger.com