Seamless Campaign Leads to RIG EK at 188.225.79.43 and Drops Ramnit

As I was checking logs in the SIEM console over the weekend I came across another detection for the Seamless campaign.

You can see from the HTTP logs that there are two direct IPs, 194.58.60.51 and 194.58.60.52, being used by the Seamless campaign.

Examining the URLs in the HTTP logs shows an interesting base64 encoded string:

The encoded string aHR0cDovLzE5NC41OC42MC41Mi9zaWdudXAzLnBocA decodes to hxxp://194[.]58[.]60[.]52/signup3.php. Below is the response from the server:

The page contains a meta refresh redirection for the Seamless gate.

Signup3.php returns the iframe for the RIG exploit kit landing page:

As per usual, the Seamless campaign used RIG EK to drop Ramnit.

Below is an image of the HTTP and DNS traffic associated with this infection chain:

We can see some hostnames being generated by the DGA in the DNS queries as well as some active C2s:

hd63ueor8473y.com at 185.20.225.138
shebkucvrunporc.com at 62.173.141.43

Following this traffic there is also a POST request to 185.156.179[.]154/jaxx/about.php:

Callback traffic used the User Agent string Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729)

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