Troj_Sirefef.kby

Posted: July 17, 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.

Threat Level:	9/10
Infected PCs:	9

First Seen:	July 17, 2012
Last Seen:	May 2, 2021
OS(es) Affected:	Windows

Troj_Sirefef.kby is a malicious DLL file that's inserted into the memory processes of other programs by associated Sirefef-based PC threats, similar to (for example) Win32/Sirefef.FB.Gen, Win32/Sirefef.FY and Trojan.Sirefef.Ga. The primary and potentially sole symptom of a Troj_Sirefef.kby-related attack is a series of alerts from relevant anti-malware and security programs, and the high degree of sophistication in Troj_Sirefef.kby's ability to hide itself makes Troj_Sirefef.kby a danger to your PC even if you can't tell if any attacks are occurring. Troj_Sirefef.kby, like many other members of the Sirefef or ZeroAccess family, is never seen by itself and includes a default support network of interrelated Trojans and rootkit components. These circumstances cause SpywareRemove.com malware researchers to recommend that you be careful to scan your entire PC to detect and remove all evidence of a Troj_Sirefef.kby infection, including its fellow PC threats, without leaving any potentially damaging software behind on your hard drive.

Troj_Sirefef.kby: When Even Windows (Unintentionally) Betrays You

Troj_Sirefef.kby, like most members of the Sirefef family, has been noted alongside a compromised services.exe file that's injected and reinjected into memory by other PC threats as necessary. Although services.exe, under normal circumstances, is a safe part of Windows, after being compromised by Troj_Sirefef.kby and related PC threats, it's used to launch Sirefef components and other PC threats that are difficult to detect or remove. Your anti-malware programs should be able to detect Troj_Sirefef.kby every time Troj_Sirefef.kby is injected into an unrelated memory process, although removing Troj_Sirefef.kby may only be possible after all related PC threats are also deleted.

Some of the other Sirefef-based rootkits and Trojans that SpywareRemove.com malware researchers have found keeping company with Troj_Sirefef.kby include Win32/Sirefef.FA, Win32/Agent.TEO and Win32/Sirefef.FB.Gen, although this isn't a conclusive list. By itself, Troj_Sirefef.kby can also be detected by various names, such as Trojan.Win32.Agent.AMN!A2 and Mal/ZAccess-X. Not all popular brands of anti-malware software have developed definitions for Troj_Sirefef.kby, although competent anti-malware scanners should still be able to detect Troj_Sirefef.kby by heuristic methods.

Wherein Lies the Real Danger of a Carefully-Concealed Troj_Sirefef.kby Infection

As the very opposite of a stand-alone PC threat, Troj_Sirefef.kby can always be considered part of an overall network of cooperative Trojans and rootkit components that work together to sabotage your PC's security. Some of the many issues that SpywareRemove.com malware experts have noticed in attacks by Troj_Sirefef.kby and other members of the Sirefef/ZeroAccess family include but aren't restricted to:

The unauthorized download and installation of other types of malicious applications.
Disabled security features and Windows security programs – with a particular focus on browser safety features that block redirects to hostile sites or warn you against downloading malicious files.
Browser hijacks that modify your online search results.
Unauthorized contact with remote IP addresses, AKA a backdoor exploit.

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:

U.ZIP

File name: U.ZIP
Size: 25.02 KB (25020 bytes)
MD5: 7ad4d2e1e450fa1f3828646ee34121ed
Detection count: 55
Mime Type: unknown/ZIP
Group: Malware file
Last Updated: July 24, 2012

C:\Windows\Installer\{f47e1dce-6863-5d23-9d0e-300d57c005d7}\U\00000001.@

File name: 00000001.@
Size: 1.69 KB (1696 bytes)
MD5: 218f559363f0be9bdf0bade486717862
Detection count: 5
Mime Type: unknown/@
Path: C:\Windows\Installer\{f47e1dce-6863-5d23-9d0e-300d57c005d7}\U\00000001.@
Group: Malware file
Last Updated: May 2, 2021