Spam Email Contains a Very Large ISO file
This zipped email attachment was received a few days ago and block by antispam policy. It contained a very large ISO/EXE file similar to the diary published by Zavier [1] last week. Instead of using Remnux, I submitted this file to a sandbox.
This is a summary of the result of the analysis. This malware communicate with the C2 site bitrat9300.duckdns[.]org over TCP/9300. This port is also used by Elasticsearch to connect to remote clusters.
Linux Command
sudo mount -o loop AMD8J46DH_ETRANFER_RECEIPT.iso /mnt
strings -t x AMD8J46DH_ETRANFER_RECEIPT.exe
File Size at Various Stages
-r-xr-xr-x. 1 guy guy 314572800 Jun 4 11:34 AMD8J46DH_ETRANFER_RECEIPT.exe
-rw-rw-r--. 1 guy guy 315176960 May 26 22:37 AMD8J46DH_ETRANFER_RECEIPT.iso
-rw-rw-r--. 1 guy guy 1888843 Jun 4 11:11 AMD8J46DH_ETRANFER_RECEIPT.zip
I noticed the EXE contained the following SmartAssembly URL. "SmartAssembly is an obfuscator that helps protect your application against reverse-engineering or modification, by making it difficult for a third-party to access your source code."[4]
http://www.smartassembly[.]com/webservices/UploadReportLogin/
http://www.smartassembly[.]com/webservices/Reporting/
http://www.smartassembly[.]com/webservices/UploadReportLogin/GetServerURL
http://www.smartassembly[.]com/webservices/Reporting/UploadReport2
VirusTotal currently doesn't have any detection for this malware, currently, Microsoft Defender detect this file as: Trojan: MSIL/AgentTelsa.AFFA!MTB [5]
Indicator of Compromise
bitrat9300.duckdns[.]org (C2)
9842e66708fabef15322d37f432929b28d60b0f240a1613454664917bcbdbf90 AMD8J46DH_ETRANFER_RECEIPT.zip
2b6edc8dd9b00ac316b6aa625f651c513ff614c01d2ca9dc55f0e4cfe5602312 AMD8J46DH_ETRANFER_RECEIPT.iso
02b1606269fdda72f84825701cba28a5a7c5f950a2b58d254b09ac35393fe81e AMD8J46DH_ETRANFER_RECEIPT.exe
Bitrat Config File
BitRat {"Host": "bitrat9300.duckdns[.]org", "Port": "9300", "Tor Port": "0", "Install Dir": "0", "Install File": "0", "Communication Password": "e10adc3949ba59abbe56e057f20f883e", "Tor Process Name": "tor"}
Setup Schedule Task
C:\Windows\SysWOW64\schtasks.exe schtasks /create /sc minute /mo 1 /tn "Nafdnasia" /tr "'C:\Users\user\AppData\Roaming\namjs.exe'" /f
[1] https://isc.sans.edu/forums/diary/A+Zip+Bomb+to+Bypass+Security+Controls+Sandboxes/28670
[2] https://otx.alienvault.com/indicator/domain/bitrat9300.duckdns.org
[3] https://cybergordon.com/result.html?id=fa580bb0-3536-40ea-a8f3-172a2a571182
[4] https://www.red-gate.com/products/dotnet-development/smartassembly/
[5] https://www.microsoft.com/en-us/wdsi/threats/malware-encyclopedia-description?Name=Trojan:MSIL/AgentTesla.BFA!MTB&ThreatID=2147782052
[6] https://malpedia.caad.fkie.fraunhofer.de/details/win.bit_rat
[7] https://www.bleepingcomputer.com/news/security/bitrat-malware-now-spreading-as-a-windows-10-license-activator/
-----------
Guy Bruneau IPSS Inc.
My Handler Page
Twitter: GuyBruneau
gbruneau at isc dot sans dot edu
Comments
Anonymous
Dec 3rd 2022
9 months ago
Anonymous
Dec 3rd 2022
9 months ago
<a hreaf="https://technolytical.com/">the social network</a> is described as follows because they respect your privacy and keep your data secure. The social networks are not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go.
<a hreaf="https://technolytical.com/">the social network</a> is not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go. The social networks only collect the minimum amount of information required for the service that they provide. Your personal information is kept private, and is never shared with other companies without your permission
Anonymous
Dec 26th 2022
8 months ago
Anonymous
Dec 26th 2022
8 months ago
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> nearest public toilet to me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
Anonymous
Dec 26th 2022
8 months ago
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> nearest public toilet to me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
Anonymous
Dec 26th 2022
8 months ago
Anonymous
Dec 26th 2022
8 months ago
https://defineprogramming.com/
Dec 26th 2022
8 months ago
distribute malware. Even if the URL listed on the ad shows a legitimate website, subsequent ad traffic can easily lead to a fake page. Different types of malware are distributed in this manner. I've seen IcedID (Bokbot), Gozi/ISFB, and various information stealers distributed through fake software websites that were provided through Google ad traffic. I submitted malicious files from this example to VirusTotal and found a low rate of detection, with some files not showing as malware at all. Additionally, domains associated with this infection frequently change. That might make it hard to detect.
https://clickercounter.org/
https://defineprogramming.com/
Dec 26th 2022
8 months ago
rthrth
Jan 2nd 2023
8 months ago