By Dancho Danchev
Its tax season and cybercriminals are mass mailing tens of thousands of IRS (Internal Revenue Service) themed emails in an attempt to trick users into thinking that their income tax refund has been “turned down”. Once users click on any of the links found in the malicious emails, they’re automatically exposed to the client-side exploits served by the Black Hole Exploit Kit.
Sample screenshot of the spamvertised email:
Sample compromised URLs participating in the campaign:
Sample client-side exploits serving URL:
Sample malicious payload dropping URL:
Malicious domain name reconnaissance:
micropowerboating.net – 22.214.171.124; 126.96.36.199 – Email: firstname.lastname@example.org
Name Server: NS1.POOPHANAM.NET – 188.8.131.52
Name Server: NS2.POOPHANAM.NET – 184.108.40.206
The following malicious domains also respond to the same IPs (220.127.116.11; 18.104.22.168) and are part of the campaign’s infrastructure:
madcambodia.net – 22.214.171.124
micropowerboating.net – 126.96.36.199
dressaytam.net – 188.8.131.52
acctnmrxm.net – 184.108.40.206
capeinn.net – 220.127.116.11
albaperu.net – 18.104.22.168
live-satellite-view.net – 22.214.171.124
morepowetradersta.com – 126.96.36.199
asistyapipressta.com – 188.8.131.52
uminteraktifcozumler.com – 184.108.40.206
rebelldagsanet.com – 220.127.116.11
madcambodia.net – 18.104.22.168
micropowerboating.net – 22.214.171.124
capeinn.net – 126.96.36.199
albaperu.net – 188.8.131.52
live-satellite-view.net – 184.108.40.206
Although the initial client-side exploits serving domain used in the campaign (micropowerboating.net) was down when we attempted to reproduce its malicious payload, we managed to reproduce the malicious payload for a different domain parked at the same IP (220.127.116.11), namely, madcambodia.net.
Detection rate for the dropped malware:
madcambodia.net – 18.104.22.168 – MD5: 2da28ae0df7a90ce89c7c43878927a9f – detected by 23 out of 45 antivirus scanners as Trojan-Spy.Win32.Zbot.ivkf.
Upon execution, the sample created the following files on the affected hosts:
C:\Documents and Settings\<USER>\Application Data\Ydukc\fuonar.exe
Set the following Registry Keys:
As well as the following Mutexes:
Once executed, the sample also phones back to the following C&C (command and control) servers:
We also got another MD5 phoning back to the same IP, MD5: c308f5c888fd97ae20eee1344f890bdb – detected by 14 out of 45 antivirus scanners as PWS:Win32/Zbot.gen!AL.
What’s also worth noting is the fact that we’ve already seen one of the domains parked at the same IPs (morepowetradersta.com) as the original client-side exploits serving domain used in the campaign in the following analyses:
- Fake ‘FedEx Online Billing – Invoice Prepared to be Paid’ themed emails lead to Black Hole Exploit Kit
- Fake LinkedIn ‘Invitation Notifications’ themed emails lead to client-side exploits and malware
Webroot SecureAnywhere users are proactively protected from these threats.