For the last few months, Symantec has been observing pharmacy related spam attacks where spammers are using the legitimate Google Translate service to avoid anti spam filters.
Most of the samples received were sent from hijacked email addresses from popular free mail services.
The majority of the messages’ subject lines were promoting either online pharmacies or well-known tablets such as Viagra, Cialis and others. Furthermore, in an effort to make the spam immune to filters, several observed subject lines contained randomized non-English characters or words inserted at the beginning or end of the subject line.
Figure 1. Sample subject lines
The body of the spam message contains a Google Translate link as well as promotional text explaining the advantages of ordering medicines from online websites, there’s even a discount code included for the reader.
Figure 2. Sample spam message
The mechanism of the redirection is quite complex. After clicking the link, Google Translate is meant to get a second address embedded in the link, which then redirects to a pharmacy website.
In our sample the final destination was the following pharmacy site:
- [http://]www.magic-pharm.com
It is worth noting that previously spammers mostly used freewebs or URL shortening services in the second part of the link (redirection link), but recently they’ve taken advantage of country IDN top-level domains, especially Cyrillic .?? domains. In redirection links, Cyrillic domains are represented in Punycode.
The following is an example of a link as it presented in a spam mail:
- [http://]www.google.com/t%72ans%6C%61%74e_p?hl=%65%6E&u=pnfd.fr.%78n–8%%330%61%66%61f0asd%62%63g.%78n-p1a%69/tipfa6eeAFLSinIMyxPMzA3NDMwMDAEACeKBEI+.aspx
Output from win-1251 decoding:
- [http://]translate.google.com/translate?hl=en&u=http://pnfd.fr.xn--80afaf0asdbcg.xn--p1ai/tipfa6eeAFLSinIMyxPMzA3NDMwMDAEACeKBEI%2520.aspx
With Punycode decoding:
- [http://]translate.google.com/translate?hl=en&u=[http://]pnfd.fr.??????????.??/ipf24aeAGzLC8vs0zJMzA3NDQ0NzAEACbKBDs .aspx
Symantec is successfully blocking the majority of variations of Google Translate redirection spam and is closely monitoring for any other inappropriate use of Google Translate services in spam email. This exploit is used in spam campaigns and has not, as yet, been observed being used in the distribution of malware.
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