first of all. That´s the Problem with signature based detection technique. So, Locky Ransomware depends on your Gateway Systems for E-Mail and Web. Signature based technique is always reactive. Signature based technique (and this is a challenge for every virusscan vendor) is often not able to detect sophisticated threads. Signature based technique needs samples to detect the "dropper" or the "infector" and so on.
We analyced some samples from customers. Any version of the Locky Ransomware was acting a little bit different. Many "things" are always random. This random "things" cannot be detected or removed by signature based technique.
Thats the reality. Fight against and you will loose. :-)
The "Locky Ransomware" executed some stuff directly from the infected Website without writing anything to the disk. But, afterwards a *.JS File was dropped on the System and afterwards executed. Now the real stuff starts......
The samples wie analyzed used SSL Connections AND connected to sites which have been hacked. No bad Reputation, no bad URL Reputation.
We checked the samples at virustotal, and it took days or weeks until the most vendors
As you can see, just to wait for a signature, you will not be able to block ransomware in the most cases.
There are many things you can do.
- If you have a email Gateway e.g. remove OLE objects from Office documents.
- Harden your Internet Proxy and inspect SSL!
- Every outbreak at our customers looked like a little bit different. We blocked some stuff with Access Protection, but at the end of the game, when a new Ransomware version arrived, we started from the beginning. *lol*
See attached an extra.dat File with some Locky detections. This might be useful.
extra.dat.zip 36.1 K
1 of 1 people found this helpful
According to VirusTotal they are on top of some more recent versions: https://www.virustotal.com/en/file/17c3d74e3c0645edb4b5145335b342d2929c92dff856c ca1a5e79fa5d935fec2/analysis/
Not sure this is a related virus, given that the "W32/Locky.worm" is a Worm dating back to 2004-04-20, long before the Ransomware Locky was developed. Seems to be an unfortunate coincidence of naming caused by the reuse of the name. Other than a name, there seems to be no relationship to the current malware called "Locky" (ransomware) which is a Word macro attack vector (and possibly Outlook/Windows Host Scripting), not a worm.
Though this should have been done years ago if Microsoft Update is used: In Word, set to "Disable all except digitally signed macros."
Additionally, limit the attack exposure by reducing Access Rights to Network Shares to the absolute minimum.
ALSO, make sure backups are current and not directly available to anyone except those responsible for the backups. Thus, if an attack is successful, restoration of encrypted files can be done after disinfecting the network or systems of Locky.
You need to supply a MD5/SHA1 hash of a file - since every vendor has their own naming convention, the hash is the only thing common that we can look up on.
There are only, oh, 200,000 new viruses/variants a day, so giving them cool names is kind of pointless.
How do i remove ole Objekts from Office Documents in the Email gateway? Do you mean macros under antivirus?