Seamless Campaign using Rig Exploit Kit to send Ramnit Trojan, (Thu, May 11th)


On Wednesday 2017-05-10, @thlnk3r tweeted about Rig exploit kit (EK) activity. @DynamicAnalysis has already posted an analysis of this traffic on (always a good read), but Ive also looked into it. Today border-width:2px” />
Shown above: Tweet about this Rig EK activity from @thlnk3r (link).


This is not one of the campaigns that use Rig EK like pseudoDarkleech or EITest (both of which I havent seen since April 2017). This traffic has different characteristics. Cisco is calling it the Seamless Campaign due to an associated iframe attribute back when it was first discovered.

By the time I investigated this traffic, the compromised site that kicked off the chain of events was already off-line. border-width:2px” />
Shown above: border-width:2px” />
Shown above: border-width:2px” />
Shown above: border-width:2px” />
Shown above: Some Ramnit alerts after reading the pcap with Snort using the Snort Subscription ruleset.

Indicators of Compromise (IOCs)

The following IP addresses and domains are associated with this traffic:

  • port 80 – – GET /flow335.php [Seamless gate]
  • port 80 – – Rig EK (1st run)
  • port 80 – – Rig EK (2nd run)
  • port 443 – – Post-infection encoded/encrypted traffic
  • Note: The infected Windows host also tried several attempts at contacting

The following files are associated with this traffic:

Final words

Rig EK is still an ongoing factor in our current threat landscape. Thanks to everyone on Twitter who tweets about EK activity. Without help from the community, this traffic is difficult to obtain.

As always, if you follow best security practices (keep your Windows computer up-to-date and patched, etc.), your risk of infection is minimal. Unfortunately, many people dont follow best practices. Until this situation changes, EKs will likely remain a profitable method for criminals distributing malware.

Emails, malware samples, and pcaps associated with the 2017-05-10 Rig EK traffic can be found here.

Brad Duncan
brad [at]

(c) SANS Internet Storm Center. Creative Commons Attribution-Noncommercial 3.0 United States License.

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