Threat Level: green Handler on Duty: Didier Stevens

SANS ISC: Angler exploit kit pushing CryptoWall 3.0 SANS ISC InfoSec Forums

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Angler exploit kit pushing CryptoWall 3.0

Introduction

In the past two days, I've infected two hosts from Angler exploit kit (EK) domains at 216.245.213.0/24.  Both hosts were infected with CryptoWall 3.0 ransomware using the same bitcoin address for the ransom payment: 16Z6sidfLrfNoxJNu4qM5zhRttJEUD3XoB

On Tuesday, 2015-05-26 at 15:17 UTC, I infected a host where Angler EK sent Bedep as a malware payload before getting CryptoWall 3.0 [1].  On Wednesday, 2015-05-27 at 17:30 UTC, I infected a host where Angler EK sent CryptoWall 3.0 as the malware payload.

I usually see Angler EK send different types of ransomware [2, 3], and I've seen plenty of CryptoWall 3.0 samples from Magnitude EK; however, this is the first time I've noticed CryptoWall from Angler EK.


Shown above: CryptWall 3.0 decrypt instructions from the 2015-05-27 sample

Traffic from the infected host

CryptoWall 3.0 traffic has changed a bit from my first diary about it on 2015-01-19 [4].  Traffic below was seen from the infected host on 2015-05-27 starting at 17:30 UTC.


Shown above: Angler EK and CryptWall 3.0 traffic as seen in Wireshark

Associated domains:

  • 216.245.213.5 port 80 - vanskeligstesjeverozapadne1.xadultchat.com - Angler EK
  • 91.184.19.41 port 80 - autorijschoolconsistent.nl - CryptoWall 3.0 check-in
  • 213.186.33.50 port 80 - jeanrey.fr - CryptoWall 3.0 check-in
  • 50.62.123.1 port 80 - 3bsgroup.com - CryptoWall 3.0 check-in
  • 75.103.83.9 port 80 - braingame.biz - CryptoWall 3.0 check-in
  • 62.221.204.114 port 80 - alsblueshelpt.nl - CryptoWall 3.0 check-in
  • 184.168.47.225 port 80 - ammorgan.net - CryptoWall 3.0 check-in
  • 79.96.220.223 port 80 - bezpiecznaswinka.pl - CryptoWall 3.0 check-in
  • 148.251.140.60 port 80 - asadiag.com - CryptoWall 3.0 check-in
  • 184.168.47.225 port 80 - alchemyofpresence.com - CryptoWall 3.0 check-in 
  • 95.163.121.105 port 80 - 7oqnsnzwwnm6zb7y.paygateawayoros.com - CryptoWall decrpyt instructions
  • 95.163.121.105 port 80 - 7oqnsnzwwnm6zb7y.paymentgateposa.com - CryptoWall decrpyt instructions
  • 7oqnsnzwwnm6zb7y.optionpaymentprak.com (didn't resolve in DNS) - CryptoWall decrpyt instructions
  • 7oqnsnzwwnm6zb7y.watchdogpayment.com (didn't resolve in DNS) - CryptoWall decrpyt instructions

Angler EK:

  • vanskeligstesjeverozapadne1.xadultchat.com - GET /molehill_inconsolably_erecting_prematureness/174208500231771131
  • vanskeligstesjeverozapadne1.xadultchat.com - GET /OEmjzR2jUP6JG0o9h494My_bK-qvpSFR6NcLcwz5j32hxI3s
  • vanskeligstesjeverozapadne1.xadultchat.com - GET /BjWMS7ksUcb9SztLJX7JlXe95voNnRcc7DfUJzRGbqTqKe8X

CryptoWall 3.0 check-in traffic:

  • ip-addr.es - GET /
  • autorijschoolconsistent.nl - POST /wp-content/plugins/revslider/temp/update_extract/revslider/img2.php?c=mr3jkiznke20nfh
  • jeanrey.fr - POST /wp-content/uploads/wpallimport/uploads/3aa8810fe8a85c3aeaf70245feaf0a41/img3.php?w=mr3jkiznke20nfh
  • 3bsgroup.com - POST /wp-content/plugins/revslider/temp/update_extract/revslider/img4.php?t=mr3jkiznke20nfh
  • braingame.biz - POST /wp-content/plugins/revslider/temp/update_extract/revslider/img4.php?x=mr3jkiznke20nfh
  • alsblueshelpt.nl - POST /wp-content/plugins/revslider/temp/update_extract/revslider/img3.php?n=mr3jkiznke20nfh
  • asambleadedios.org - POST /wp-content/plugins/revslider/temp/update_extract/revslider/img5.php?z=mr3jkiznke20nfh
  • ammorgan.net - POST /wp-content/plugins/revslider/temp/update_extract/revslider/img5.php?o=mr3jkiznke20nfh
  • bezpiecznaswinka.pl - POST /wp-content/plugins/revslider/temp/update_extract/revslider/img2.php?k=mr3jkiznke20nfh
  • asadiag.com - POST /wp-content/plugins/revslider/temp/update_extract/revslider/img4.php?q=mr3jkiznke20nfh
  • alchemyofpresence.com - POST /wp-content/plugins/revslider/temp/update_extract/revslider/img4.php?z=mr3jkiznke20nfh

Note: These URLs repeated several times with different random strings at the end.

Traffic caused by viewing the CryptoWall decrypt instructions in a browser:

  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /1kwN8ko
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /img/style.css
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /img/flags/us.png
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /img/flags/it.png
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /img/rt.png
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /img/flags/fr.png
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /picture.php?k=1kwn8ko&4d2156f57fb503178f62c2f95690e599
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /img/rb.png
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /img/flags/es.png
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /img/flags/de.png
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /img/lb.png
  • 7oqnsnzwwnm6zb7y.paygateawayoros.com - GET /img/lt.png


Shown above: Emerging Threats-based Snort events on the infection traffic using Security Onion

Preliminary malware analysis

Malware payload delivered by Angler EK on 2015-05-27:

Final words

A pcap of the 2015-05-27 infection traffic is available at:

A zip file of the associated malware is available at:

The zip file is password-protected with the standard password.  If you don't know it, email admin@malware-traffic-analysis.net and ask.

---
Brad Duncan
ISC Handler and Security Researcher at Rackspace
Blog: www.malware-traffic-analysis.net - Twitter: @malware_traffic

References:

[1] http://malware-traffic-analysis.net/2015/05/26/index.html
[2] https://isc.sans.edu/diary/Angler+exploit+kit+pushes+new+variant+of+ransomware/19681
[3] http://malware-traffic-analysis.net/2015/03/25/index.html
[4] https://isc.sans.edu/diary/Traffic+Patterns+For+CryptoWall+30/19203

 Brad

350 Posts
ISC Handler
Subscribe May 28th 2015
4 years ago
I just had a customer infected about 4 days ago.

I took a VM image of their machine before I trashed the hard drive.

Can I help in anyway to help find these punks.

I took a wireshark trace and ip points to 95.163.121.105

Not sure if it is proxy or what, but would love to help if I can in anyway.

Thanks,

Silent
 Anonymous
Quote Jun 3rd 2015
4 years ago
Silent,

Thanks for the information! 95.163.121.105 is one of the websites used to view the decrypt instructions (as shown in the blog entry). It's not uncommon to see the same IP address space used for a long period of time. Hopefully, it will help as an indicator of compromise for others. Thanks again.

- Brad
 Brad

350 Posts
ISC Handler
Quote Jun 3rd 2015
4 years ago

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