This article explains why the BitDefender signature value decreases.
The following information is provided by BitDefender:
The virus signatures contain possible locations for certain infected files, strings of code that should belong to certain malware, and instructions (also known as disinfection routines) on how to remove the malware itself. It is possible for the malware signature number to decrease due to the following reasons:
- A group of signatures can be removed and be replaced by only one signature that applies to one family of infections (e.g. Sirefef, TDSS, Brontok).
- Individual signatures for members of the malware family may be combined into a single signature after gathering all the necessary information regarding the family.
- The removal of False Positive signatures.