Tuesday, April 8, 2014

New Analysis Apr 8 2014

Hi everyone. I'm trying to get into doing analysis regularly. So today I present another blog.

Today I did an analysis on a piece of malware filename 163842953.exe
MD5: 84e5e263ff859dae0df198c2b9051cf8 There is no clear consensus on what the Malware is on virustotal, and it has a horrendously low detection rate with the engines. (https://www.virustotal.com/en/file/da958d67485d4162f374fca97c3cfdd060aabb1ca49351efabdb5c4f414b2dd9/analysis/)

Here is a basic rundown on what I was able to find. When executed the file excuses cmd.exe silently and drops the following files:
File.exe: F2D365780E7DD0691C6FFB0EB888CABA
hhhii.exe: 53E9C0B26A983F00CD625BF2A1EB419B
mmmhhee.exe: 0EAAA93B405EC6B42121066646C56958

There is slightly better coverage for these files on the AV engines, excluding the last file which appears to have the job of performing reachback.

Speaking of which we saw a few URLs requested in this sample. IIRC, all requests were sent on port 80.
dupler-histu.com GET /b/shoe/456 HTTP/1.1
kozzi-acompany.com   GET /libk25.98/jquery/ multiple requests for this file.
GET /wpad.dat HTTP/1.1 User-Agent: System.Net.AutoWebProxyScriptEngine/2.0.50727.4927
mirutaruda.com  GET /startloader HTTP/1.1 GET /style.css HTTP/1.1 -  mmmhhee.exe is linked to this domain according to virustotal.
krowdclown.com GET /style.css HTTP/1.1  multiple requests for this file.

Now i'm no registry expert, so crawling through the entries was not easy, but I did notice these strange entries:
HKU\USER SID\Software\Cpvnutujyk - SID removed
HKLM\SOFTWARE\Wow6432Node\Cpvnutujyk\License: 0x000001C8

So thats what I got today, please leave feedback, thanks! EDIT: A comment on one of the reports links one of the domains to ASPROX, Unconfirmed, but certainly possible.

Friday, April 4, 2014

New analysis

Hey all,

I know its been a while since I posted, events events. After my first analysis I received a naughtygram form my ISP, actually just them letting me know that I might be infected! Well, I took some time and eventually found some new ways to do my analysis, hopefully with less risk. I do want to take a second to give a shout to TekDefense and their YouTube channel https://www.youtube.com/user/TekDefense - some great videos there with introductions to Malware Analysis. So since this is my first real day back, i'll just review some info. Yesterday I was able to get my Security Onion (https://code.google.com/p/security-onion/)distro back up and running, and was able to test it out, so the goal is to do separate tests now, and perhaps at some point to integrate malware analysis and IDS testing, seeing what the IDS detects, and writing custom rules to detect what it misses.  So what did I see today from this version of cryptolocker? Probably not much that wouldn't be found in an in depth analysis paper written by an experienced analyst with hours to examine it, but I did notice a few things. The original file (Sorry, I don't have the name) spawned a new process, windtre.exe. windtre can be found in the user's temp directory and has an MD5 of 2BEDEF64E5A615619356219E44E5082D which was not in Virustotal. In the future I will be looking for ways to safely upload these files to sites for further analysis. Finally the malware did make some get requests for wpad.dat unfortunately I missed the ip's it requested. Future analysis reports will have this info, but i'll have to do it on days where I don't have to work! Well, thanks for reading guys, hope you all have a great day, please leave feedback. - SecTest