Spam Email Contains a Very Large ISO file

Published: 2022-06-04
Last Updated: 2022-06-04 16:55:59 UTC
by Guy Bruneau (Version: 1)
0 comment(s)

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

0 comment(s)

Comments

cwqwqwq
eweew<a href="https://www.seocheckin.com/edu-sites-list/">mashood</a>
WQwqwqwq[url=https://www.seocheckin.com/edu-sites-list/]mashood[/url]
dwqqqwqwq mashood
[https://isc.sans.edu/diary.html](https://isc.sans.edu/diary.html)
[https://isc.sans.edu/diary.html | https://isc.sans.edu/diary.html]
What's this all about ..?
password reveal .
<a hreaf="https://technolytical.com/">the social network</a> is described as follows because they respect your privacy and keep your data secure:

<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
https://thehomestore.com.pk/

Diary Archives