Last year (http://www.eset.com/threat-center/blog/2009/09/03/more-infections-a-lot-more-malware), we posted statistics collected through our online scanner logs.  Below, you will find updated statistics on the number of infected  hosts, malicious files and malware families found on infected systems.

In general, the statistics we are seeing in through our online scanner logs are consistent with our observation from last September.  We are seeing an average of 3 different malware families per infected computers.  This means that on average, when a computer is infected, we find three different malware families installed ont it.  An interesting point is that this average seems to be slowly but steadily going down each month.  This might indicate that malware operators are consolidating their operations.  There might starting to perform more actions with one program instead of installing different malware after an intrusion.

The average of different malware families per infected hosts in the United States is close to the global average.  On the other hand, this number reaches 4.5 in China where it has one of the highest value.  This indicates that malware operations are not conducted the same way around the world.  We usually see less bank information stealers in Asia but more online game password stealers.  Online game password stealers are usually installed by other malware families and don’t propagate by themselves, explaining why we see an higher average in China than in the United States.
 
On a daily basis, ESET is collecting more than 200 000 new and unique binary malicious files, this number is higher than the statistics published last year.  This means that by the time you are finished reading this blog post, at least 70 unique pieces of malware will be produced!

Pierre-Marc Bureau
Sr. Malware Researcher