Worse Than CryptoLocker
The competition to copy CryptoLocker is heating up and the latest variation is even more technically sophisticated.–PC Pitstop
By Stu Sjouwerman, for KnowBe4.com Security Awareness Training
As we said before, there is furious competition between cybergangs. Late February 2014, a CryptoLocker ransomware copycat competitor called CryptoDefense was released which outdoes the original.
They did their test-marketing in many other countries like the UK, Canada, Australia and others. They are now targeting the U.S. as you can see in this infection heatmap picture generated by Symantec. They are making tens of thousands of dollars per month with this technically sophisticated scam.
If an end-user opens the infected attachment, the CryptoDefense ransomware encrypts its target files, and the criminals charge approx. $U.S. 500 in Bitcoin to decrypt the files. If their four-day deadline passes by, the amount goes to about $U.S. 1,000. Note that Bitcoin exchange rates vary so these numbers are ballpark, and that CryptoDefense is much more expensive to unlock than CryptoLocker.
The ransomware target files are text, picture, video, PDF and MS Office files and CryptoDefense encrypts these with a strong RSA-2048 key which is hard to undo. To add insult to injury, it wipes out all Shadow Volume Copies. Instructions with the ransom demands are added to every folder containing encrypted files. This stinks.
When the hapless end-user clicks the attachment, CryptoDefense connects to four remote domains and sends basic information about the infected workstation. Then, the files on the end-user machine are encrypted, and the private key is sent back to the Control & Command server.
Last, the malware makes a screenshot of the active screen of the end-user workstation and uploads this to their C&C server. That screenshot appears on the payment page where the victim can upload the Bitcoin payments. To reach this page you first need to install the Tor Browser as the payment page is only available via the Tor network, which helps the criminals hide from the law to some degree.
This excerpt appears with permission from knowbe4.com.
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