UK Tax-Themed Spam Leads to ZeuS/ZBOT

Tax-themed spam, particularly in the United States, is already considered a staple in the threat landscape. However, a recent spam run targeting taxpayers in the United Kingdom shows that this threat is never exclusive to a region. Besides being timely, these messages contain TSPY_FAREIT, which download a ZeuS/ZBOT variant, notorious for stealing information related to online banking sites.

We found sample of an email message that appears to be from HM Revenue and Customs in the UK. It notifies users of their VAT return receipt, something that might appear timely to unsuspecting users since the deadline for VAT returns and payments was last August 7. To further convince users of its validity, the message states that the email was “scanned for viruses”.

Sample spam with alleged VAT return “receipt”

The message contains an attachment, which is supposed to be the receipt for the VAT return. But based on our findings, the attachment is (expectedly) a malware detected as TSPY_FAREIT.ADI. Once executed, the malware steals varied information from the system, such as those related to: FTP clients,file managers, and email. It also attempts to steal information stored in the following browsers:

FastStone Browser
Flock Browser
Google Chrome
Internet Explorer
K-Meleon
Mozilla Firefox
Opera Browser
RockMelt

The data stealing does not stop there. TSPY_FAREIT.ADI downloads another malware, specifically TSPY_ZBOT.ADD. As expected of any ZeuS/ZBOT variant, the malware downloads configuration file(s) from randomly generated IP addresses. The said file also contains list of targeted online banking and finance-related sites and the URLs where it sends the gathered information.

The cybercriminals behind this threat are obviously taking advantage of the recent tax return deadline in the UK. But the real concern here is the severity of the information to be stolen. Aside from the email and FTP credentials, which are profitable in the underground market, the bad guys are also gunning for the victims’ online banking accounts. Once they got hold of users’ banking and financial credentials, they can either sell them on the digital underground or use these to initiate unauthorized money transfers leading to actual financial loss.

In our 2Q Security Roundup report, we noted the increase of online banking malware in the past quarter and how the CARBERP’s “leaked” source code may lead to more variety for this threat. Thus, it is important for users to double-check the messages they receive and to be careful in opening any attachments from unverified sources. As an added precaution, always implement your systems with the latest security updates from vendors.

For more information on how to avoid threats using social engineering lures, you may refer to our Digital Life e-Guide How Social Engineering Works. Trend Micro blocks these email messages and detects the related malware.

With additional insights from Threat Response Engineer Anthony Joe Melgarejo

Post from: Trendlabs Security Intelligence Blog – by Trend Micro

UK Tax-Themed Spam Leads to ZeuS/ZBOT