Posted by Virus Bulletin on Apr 23, 2014
AOL responds by following Yahoo! in setting strict DMARC policy.
This week, #AOLhacked has become a popular hashtag on Twitter: many AOL users are using it to complain that their email address had been sending spam to their contacts.
Those who click the link in the emails - never a wise thing to do unless you are in a safe environment - are presented a harmless website promising a miracle diet, as Graham Cluley points out.
But things are a little different when the URL is opened on an Android device, or with a user agent set to make the browser appear to be running on Android. In that case, through a number of redirects, a variant of the 'NotCompatible' trojan is downloaded.
The variant is at least a month old and is detected by a large number of anti-virus products. Of course, this isn't much help if users don't run anti-virus on their Android devices.
The payload is downloaded from the domain androidsslfix[.]ru. It is likely that those who registered this domain last week did so with a number of recent bugs in SSL implementations in mind.
In most (though not all) cases, the sender of the emails appears to be spoofed and the emails aren't actually sent from AOL's servers. As AOL writes, there is nothing an email user can do against emails pretending to be sent from their address.
But that is only part of the problem. The fact that emails are being sent to the addresses in the sender's address book points to some kind of leak, either with the user or at AOL's end. It is currently unclear which of the two is the case, but it would be helpful if AOL were at least to acknowledge this. It is also good to note that in some cases the emails are actually sent from servers belonging to AOL.
The current campaign reminds me of what we've been seeing at Yahoo for over a year, where apparently compromised accounts have been sending links that spread the same 'NotCompatible' trojan. There have even been some suggestions that the two campaigns are linked, though I have not found any evidence for this myself.
Interestingly, in response to these events AOL follows what Yahoo! did recently and set a strict DMARC policy. While this would indeed help receiving mail servers block emails from spoofed AOL accounts, it does so at no insignificant cost.
Posted on 23 April 2014 by Martijn Grooten