All Spammed Up has a new post up referencing an article that security researchers have issued a report indicating that Spain is the country with the most infected computers, at 44.5%. The United States is second at 14.4%. The countries with the least infections are Sweden, The Netherlands and Peru.
The Microsoft Security and Intelligence Report, v7, doesn’t measure infection rates quite the same way. Instead, it has a metric called Computers Cleaned per Thousand machines scanned, or CCM (where M is the Latin word for thousand – mille). This is a measure of the number of computers cleaned per thousand executions of the Malicious Software Removal Tool (MSRT). Below is a heat map of the countries with the most infections, for a better image either click the image (as it will be cut off in this blog) below or download the full report and zoom in your Adobe pdf reader (it is on page 41):
Going from the above, we can see that Spain is definitely one of the hotter countries. But, it is not the hottest. Below is a table of the countries with the worst rates of infection:
Spain is clearly one of the worst but it is actually only number 4 behind Serbia and Montenegro, Turkey and Brazil. There is no set pattern but in general, countries in the developed world (at the very least, the G7) are not found among the worst countries for malware infection. Of course, the very interesting thing is that even within different countries, the types of infections are different. Microsoft classifies the types of malware it removes and below is a table of what it looks like among various countries. Click on the picture to see the full image as it will be cut off partially in this blog:
From our table above, Brazil and Spain are the worst offenders for malware infected computers, coming in at 3 and 4 respectively. Yet the type of malware hitting them is different. Brazil is plagued by Password Stealers that target Brazilian banks (led Win32/Bancos), followed by Worms and Viruses. by contrast, Spain is hit hardest by Worms, then miscellaneous trojans and password stealers, which are substantially less than Brazil.
The United States was number 2 in the report that All Spammed Up referenced, but the most common malware affecting systems in the US are miscellaneous trojans, followed by trojan downloaders and droppers and then Adware (the pattern is similar in the United Kingdom). So, different regions of the world are more prone to certain types of attacks than others.
If we can make a generalization, then the countries with the highest malware infections rates as measured by the MSRT CCM metric are more prone to Worms. The United States is actually about average with regards to infection (8.6 CCM vs 8.7 global average). With regards to the lower countries, I am currently not seeing any discernable pattern and I would have to do a deeper statistical investigation.