Preventing ISO Malware
In the last few weeks, I’ve seen a significant uptick in systems infected with Chromeloader malware. This malware is a malicious extension for your browser, redirecting it to ad sites and hijacking searches. But with the success of this technique recently, I would not be surprised if others will take notice and switch to using it for other things.
Initial infection
The user went to the malicious search results, where the query they searched for presented an ISO file for their search terms. Below is the results of a user that got infected
https://alizebruisiacult[.]xyz/?cms=Mzg1ODEEDwwMCAYNDQwCAQsCDNDEDgcCDwwPAQAASQ%3D%3D&fn=Stroud%20-%20Advanced%20Engineering%20Mathematics%204e&extt=xpectthatmy.shop%2F%3Ftid%3D952736
C:\Users\user\Downloads\Stroud - Advanced Engineering Mathematics 4e.iso
This ISO file contained the following files
files.zip
res.ico
Install.lnk
properties.bat
The user double clicked on the Properties.bat file that started the infection process.
Parent Process Name: cmd.exe
Parent Process Command Line: cmd.exe /c ""D:\properties.bat" "
Process Name: tar.exe
Process Command Line arguments: tar -xvf "files.zip" -C "C:\Users\user\AppData\Roaming"
They established persistence with CurrentVersion\Run key.
"opensubtitles-uploader.exe "k2eN"" /f.
HKEY_CURRENT_USER\S-1-5-21-740110469-27406-3214746-20027\SOFTWARE\Microsoft\Windows\CurrentVersion\
C:\Users\user\AppData\Roaming\opensubtitles-uploader\opensubtitles-uploader.exe.
Connection to some malicious domains from happened from opensubtitles-uploader.exe.
C:\Users\user\AppData\Roaming\opensubtitles-uploader\opensubtitles-uploader.exe.
https://alizebruisiacult[.]xyz
https://raw.githubusercontent[.]com
Since the infection is coming from a user mounting and executing files in an ISO, the best way to stop this is to prevent a user from mounting the ISO by double clicking. Users are still able to Burn a CD from within windows if needed. If you have power users that need to open ISOs they can use compression utilities.
Mubix (Rob Fuller) has a great article about how to disable this.(1). Below, there are two different options to prevent users from double clicking ISO file to mount them. The GPO method is a little more complete in protections, see the article for more details. We have deployed this in my environment to end users' desktops and have not had any issues to this point nor any new infections via this method.
GPO
Computer config -> Admin Templates -> System -> Device Installation Restrictions ->
- Allow administrators to override Device Installation Restrictions Policies (enabled)
- Prevent Installation from devices that match any of these device IDs
Add this exact ID
- SCSI\CdRomMsft____Virtual_DVD-ROM_
Registry Setting
- HKEY_CLASSES_ROOT\Windows.IsoFile\shell\mount
- Value “ProgrammaticAccessOnly” as REG_SZ
(1) https://malicious.link/post/2022/blocking-iso-mounting/
If you have done this or something similar, let us know.
--
Tom Webb
@twsecblog
Video: Grep & Tail -f With Notepad++
This is a video for diary entry "Quickie: Grep & Tail -f With Notepad++".
Didier Stevens
Senior handler
Microsoft MVP
blog.DidierStevens.com
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
9 months ago
Anonymous
Dec 26th 2022
9 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
9 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
9 months ago
Anonymous
Dec 26th 2022
9 months ago
https://defineprogramming.com/
Dec 26th 2022
9 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
9 months ago
rthrth
Jan 2nd 2023
8 months ago