New form of malware has been reported to cause infections via a vulnerability for Windows Machines that is 17 years old. The virus, related to the pen-testing (penetration testing) tool Cobalt Strike is also dubbed Cobalt Strike malware and it’s primary goal after infecting your computer is to turn it into a slave of the hackers who are behind the infection. In the event that you have seen W32/Cobalt or other similar detection on your computer, we recommend that you read this article and learn how to fully remove the Cobalt Strike malware from your PC and protect it against future infections and intrusions.
|Name||Cobalt Strike Malware, also known as PUP.DllInject.G|
|Short Description||Aims to make your computer remotely controlled via shell commands by the hackers behind the virus.|
|Symptoms||No symptoms so far as the malware is file-less, but your computer may behave strange and can contain other malware in it.|
|Distribution Method||Via malicious URLs or compromised websites.|
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|User Experience||Join Our Forum to Discuss Cobalt Strike Malware.|
Cobalt Strike Malware – Infection Analysis
In order to cause a successful infection, the malicious file of this virus is actually a semi-legitimate Microsoft Word document, which pretends to be a legitimate file sent by a bank or a big company. The file itself infects via malicious macros which contain the exploit CVE-2017-11882 that is over 17 years old at the time of writing this. So far, what is known about this vulnerability is that it was only patched once, two weeks after it was discovered by Microsoft.
The way the cyber-criminals who are believed to be the Cobalt hacker group have decided to use malicious macro infections for their attacks in e-mails that they pretend are from Visa. One sample was detected by malware researchers Jasper Manual and Joie Salvio at Fortinet and it uses the following e-mail:
The message (In Russian) pretends to come from Visa’s payWave system and it aims to get the victim to open what appears to be a .zip and .doc files that pose as “New security system changes in Visa payWave”. Once this document is opened, the victim sees a legitimate Microsoft Word file that only says the words “Enable Editing”:
When this .ps1 file is executed, the actual Cobalt Strike infection takes place on the victim’s computer.
Cobalt Strike Malware – Malicious Activity
Once downloaded, the .ps1 file, belonging to Cobalt Strike is automatically activated. It triggers yet another PowerShell script which has the client DLL files of Cobalt Strike – a rather outdated, but still very effective tool, previously used for penetration testing of the defenses in Windows Operating Systems. Once it detects whether your Windows is running based on 32-bit or 63-bit architecture, the appropriate Cobalt Strike DLL is executed directly in your Windows PowerShell memory and this results in the malware not being actually present on your drive, while remaining embedded in PowerShell and even if you delete the .ps1 file, the virus is still active on your PC. This also helps any antivirus programs that are conventional to detect the virus.
Once the DLL of Cobalt Strike is triggered, the cyber-criminals have obtained complete control of your computer system – it belongs to them. They can perform all of the activities which can be performed using the Cobalt Strike shell commands themselves. Here is only a small part of commands that may be triggered, using Cobalt malware:
→ spawnto – spawns sessions into processes.
inject – injects various malicious scripts in legitimate Windows processes.
dllinject – same as inject but for DLLs
download – can download other malware or files on your computer.
upload – can upload files to the hacker’s server, i.e. it can steal your files.
timestomp – to assist with blending files, obfuscation and updating itself.
ls – similar to Linux, it helps you to list different files.
mkdir – to create folders on your computer.
keylogger pid – to log your keystrokes.
screenshot pid – to take a screenshot of your desktop.
jobkill – to kill a job.
socks 8080 – to set a Proxy server on a selected port (in this case 8080).
These are only the main commands that are likely to be used on your computer and you have no way of knowing that they are triggered as it all happens in the background of your computer. The full list of commands can be seen on Cobalt Strike’s web page.
How to Remove Cobalt Strike Malware from Your PC
Preparation before removing Cobalt Strike Malware.
Before starting the actual removal process, we recommend that you do the following preparation steps.
- Make sure you have these instructions always open and in front of your eyes.
- Do a backup of all of your files, even if they could be damaged. You should back up your data with a cloud backup solution and insure your files against any type of loss, even from the most severe threats.
- Be patient as this could take a while.
Cobalt Strike Malware FAQ
What Does Cobalt Strike Malware Trojan Do?
The Cobalt Strike Malware Trojan is a malicious computer program designed to disrupt, damage, or gain unauthorized access to a computer system.
It can be used to steal sensitive data, gain control over a system, or launch other malicious activities.
What Damage Can Cobalt Strike Malware Trojan Cause?
The Cobalt Strike Malware Trojan is a malicious type of malware that can cause significant damage to computers, networks and data.
It can be used to steal information, take control of systems, and spread other malicious viruses and malware.
Is Cobalt Strike Malware Trojan a Harmful Virus?
Yes, it is. A Trojan is a type of malicious software that is used to gain unauthorized access to a person's device or system. It can damage files, delete data, and even steal confidential information.
Can Trojans Steal Passwords?
Yes, Trojans, like Cobalt Strike Malware, can steal passwords. These malicious programs are designed to gain access to a user's computer, spy on victims and steal sensitive information such as banking details and passwords.
Can Cobalt Strike Malware Trojan Hide Itself?
Yes, it can. A Trojan can use various techniques to mask itself, including rootkits, encryption, and obfuscation, to hide from security scanners and evade detection.
Can a Trojan be Removed by Factory Reset?
Yes, a Trojan can be removed by factory resetting your device. This is because it will restore the device to its original state, eliminating any malicious software that may have been installed.
Can Cobalt Strike Malware Trojan Infect WiFi?
Yes, it is possible for a Trojan to infect WiFi networks. When a user connects to the infected network, the Trojan can spread to other connected devices and can access sensitive information on the network.
Can Trojans Be Deleted?
Yes, Trojans can be deleted. This is typically done by running a powerful anti-virus or anti-malware program that is designed to detect and remove malicious files. In some cases, manual deletion of the Trojan may also be necessary.
Can Trojans Steal Files?
Yes, Trojans can steal files if they are installed on a computer. This is done by allowing the malware author or user to gain access to the computer and then steal the files stored on it.
Which Anti-Malware Can Remove Trojans?
Anti-malware programs such as SpyHunter are capable of scanning for and removing Trojans from your computer. It is important to keep your anti-malware up to date and regularly scan your system for any malicious software.
About the Cobalt Strike Malware Research
The content we publish on SensorsTechForum.com, this Cobalt Strike Malware how-to removal guide included, is the outcome of extensive research, hard work and our team’s devotion to help you remove the specific trojan problem.
How did we conduct the research on Cobalt Strike Malware?
Please note that our research is based on an independent investigation. We are in contact with independent security researchers, thanks to which we receive daily updates on the latest malware definitions, including the various types of trojans (backdoor, downloader, infostealer, ransom, etc.)
Furthermore, the research behind the Cobalt Strike Malware threat is backed with VirusTotal.
To better understand the threat posed by trojans, please refer to the following articles which provide knowledgeable details.