Dorifel is much bigger than expected and it’s still active and growing!
Yesterday it was a dark day for many companies in Europe, but especially in the Netherlands. A piece of malware known as Worm.Win32.Dorifel infected over 3000 machines globally, and 90% of infected users were both from public and business sector organizations based in the Netherlands. We have seen government departments and hospitals being victims. The other countries with a large amount of infections were detected in Denmark, the Philippines, Germany, the United States and Spain. All users running Kaspersky Lab’s Products are protected from this threat.
The malware is initially distributed via email to victims. It uses a “Right To Left” vulnerability to hide its original file extension. The malware then downloads another malware which encrypts documents and executes them on the infected computer. Dorifel also attempts to encrypt files found on network shares.
When I was sitting down and investigating the Dorifel malware I noticed that the servers hosting the Dorifel malware was not configured properly and allowed for example directory listing in certain directories. This triggered me to search for more interesting directories, which I did and to my surprise I noticed that the server was hosting a lot more malicious “components” and not just the Dorifel malware. It is very difficult to say if this scam is complex and advanced since it uses many different components with different complexity level. Some of the interesting things I found includes: