As of May 20th, Microsoft Removal Tool (MSRT) disinfected 52,549 computers from the Win32/Ramnit infection, revealed MMPC blog. Ramnit is one of the four parasitic viruses out of the top 10 detected threat families. Win32/Ramnit was added to MSRT detection capability, last month.
You may notice that Ramnit is classified as an "evolved" virus in the chart.
"A parasitic virus, or a file infector, is a type of "old school" malware that attaches, modifies or resides in a host file on the file system. Due to its invasive spreading technique, one may wonder why malware are still in love with this old method, particularly when file infectors tend to leave the computer in an unstable state, slow and crashing often, while some even render the infected computer useless," explained Scott Wu.
"With today's malware authors aiming to make profit from their victims, one would expect the malware authors are motivated to create stealth threats with the least overhead to the machine as to keep the windows of time open long enough to harvest data (or perform other payloads)."
Parasite viruses are not going away, they are still relevant and evolving.
Top 25 detections by MSRT, May 10 - May 20
|Sality||202,351||Classic parasitic virus|
|Jeefo||22,396||Classic parasitic virus|
|Virut||20,963||Classic parasitic virus|