Orcus RAT

Orcus is a modular Remote Access Trojan with some unusual functions. This RAT enables attackers to create plugins using a custom development library and offers very robust core featureset, that make it one of the most dangerous malicious programs in its class.

Type
RAT
Origin
Canada
First seen
1 April, 2016
Last seen
19 January, 2021
Also known as
Schnorchel
Global rank
24
Week rank
8
Month rank
14
IOCs
2220

What is Orcus RAT?

Orcus, previously known as Schnorchel, is a Remote Access Trojan — a malware that enables remote control of infected systems. Although Orcus RAT malware is mostly a typical member of the RAT family, it has some competitive advantages over similar malware and unique features.

In addition, Orcus RAT has a modular structure and it gives users the ability to create custom plugins for the malware. The modularity of this trojan gives it higher than standard scalability and management, allowing to tailor the malware to the needs of various campaigns.

The first time we heard about this malware was from a forum post by one of its authors. The post announced the development of a new RAT that was named Schnorchel at the time. Soon after the announcement, the malware became commercially available under the name “Orcus RAT” and was presented to the public as a legal software for remote administration, similar to Teamviewer. Interestingly, authors claimed that the abbreviation RAT stood for Remote Administration Tool and not Remote Access Trojan.

General description of Orcus RAT

Apart from a few exceptions, Orcus RAT malware has a relatively standard but robust feature set for a technologically advanced Remote Access Trojan. The malware can grab screenshots and record user input, activate the webcam, steal passwords, record audio and steal information. In addition, Orcus comes with the ability to detect if it’s being launched on a virtual machine to complicate the analysis by security researchers.

The functions described above already make this malware quite capable, however, it offers a few unusual functions that enhance its functionality. Namely, the RAT in question supports plugins and besides offering the ability to build them, it has a whole library of already created plugins that attackers can choose from. Orcus RAT plugins can be written in multiple languages, including C#, C++, and VB.Net.

To make the development of extensions more streamlined, malware creators rolled out a dedicated development environment. What’s more, those who lack the skills to build plugins from scratch on their own can follow detailed tutorials and benefit from well-maintained documentation libraries.

Additionally, Orcus had a Github page where authors have published samples of created plugins.

Another relatively unique feature that the malware authors packed into this virus is real-time scripting. Real-time scripting allows Orcus to write and run code on machines that it infected.

Speaking of Orcus RAT malware authors, we know that the virus was being developed by a 36-year-old John Revesz also known as “Armada" on the underground forums. In 2019, Canadian authorities accused Revesz of operating an international malware distribution scheme.

In his defense, Revesz claimed that the RAT is, in fact, a legitimate program for remote administration and his company “Orcus Technologies” is a legal business. However, an examination of the functionality clearly revealed that the software is intended for malicious use cases, which resulted in the arrest of Revesz.

It is believed that Revesz wasn’t working alone. A joint development effort theory makes sense, especially considering the technological complexity of certain aspects of this malware. For example, Orcus RAT consists of multiple components with the control panel being a separate component. The server that the malware establishes a connection with after infection does not hold an admin panel. This architecture provides several advantages to the attackers, for example, the ability to share access to infected PCs from the same server. Additionally, it allows for greater scalability or infected networks.

Orcus RAT malware analysis

A video recorded in the ANY.RUN interactive malware hunting service displays the execution process of Orcus RAT in real-time.

process_graph_of_orcus_rat_execution

Figure 1: Displays the execution process of the Orcus RAT. This visualization was generated by ANY.RUN.

text_report_of_orcus_rat_execution

Figure 2: Displays a text report generated by ANY.RUN. Text reports are useful for demonstration and can be customized by a user to show necessary data.

Orcus RAT execution process

The execution process of the Orcus RAT is simple and straightforward. This malware often disguises itself as some kind of cheat code or crack so it is mostly delivered to a system as an archive file with the compressed executable file inside. Since this trojan was written in C#, it often uses .NET infrastructure which is available in Windows. To compile the C# source code our sample started Visual C# compiler which, in turn, started the Resource File To COFF Object Conversion Utility. After it was compiled, the executable file began its execution and malicious activity. Note that Orcus remote access tool does not always make its way into an infected system as described above. In some cases, it comes as a precompiled executable file which only needs a user to double click on it to start the execution.

Orcus RAT malware distribution

Orcus RAT commonly makes its way into target machines as a downloadable attachment in malicious spam emails. Campaigns are often highly targeted and aim at organizations rather than at individuals.

Attackers use phishing and social engineering to trick victims into downloading an attachment or visiting a link that points to a server that holds the payload. In order to begin execution Orcus does require user input, in most cases it is unable to infect the system without user interaction.

How to detect Orcus RAT?

This malware creates files that allow analysts to detect it with a high degree of certainty. To identify the Orcus RAT, open the "Advanced details of process" by clicking on the "More info" button and switch events display to "Raw". This trojan often creates files with "Orcus" in the names, so all we need is to find such a file. To make it easier just type the word "Orcus" in the filename field. If such a file is found, you can be sure that Orcus RAT is in front of you.

files_created_by_orcus_rat

Figure 3: Files created by Orcus RAT

Conclusion

Orcus RAT malware is a sophisticated trojan that offers some unusual functions on top of solid basic info-stealing capabilities. Technical complexity was complemented by an affordable price of just 40 USD. Today, interested users can download a leaked version of Orcus for free. Unfortunately, this along with excellent support and documentation ensured the popularity of Orcus RAT.

Since its deployment in 2016, researchers have been observing Orcus RAT campaigns and the popularity of this malware is still on the rise. We can expect several new attacks utilizing malicious software in the future.

Researchers can analyze Orcus RAT using the ANY.RUN malware hunting service to study this malware. ANY.RUN is an interactive sandbox that allows researchers to stop and correct the simulation at any point which ensures pure research results. Useful information that can be obtained from the analysis can be added to our growing database of cyber threats to help combat internet crime all around the world.

IOCs

IP addresses
193.161.193.99
51.75.39.41
3.131.147.49
3.133.207.110
3.134.39.220
3.134.125.175
3.14.182.203
3.17.7.232
3.13.191.225
3.14.64.91
3.22.30.40
194.34.132.153
92.222.72.160
13.58.162.35
18.222.116.179
76.175.159.207
91.109.182.3
91.109.190.2
91.109.180.4
18.197.239.5
Hashes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2.tcp.ngrok.io
isns.net
4.tcp.ngrok.io
majul.com
99e94c1ba867.ngrok.io
8dc90d45961e.ngrok.io
9813b3e1debe.ngrok.io
compte-client-ameli-remboursement-fr.ngrok.io
05eca2b70a29.ngrok.io
a234b459b6e0.ngrok.io
a234b459b6e0.ngrok.io
28e8ad52aeaf.ngrok.io
bbcadd17adea.ngrok.io
d6e52dc32552.ngrok.io
ac44c74bafd5.ngrok.io
3ee6f20d23fb.ngrok.io
29eb5becd65d.ngrok.io
d5dfc64463e6.ngrok.io
66d5a675.ngrok.io
1.tcp.ngrok.io

HAVE A LOOK AT

Adwind screenshot
Adwind
adwind trojan
Adwind RAT, sometimes also called Unrecom, Sockrat, Frutas, jRat and JSocket is a Malware As A Service Remote Access Trojan that attackers can use to collect information from infected machines. It was one of the most popular RATs in the market in 2015.
Read More
Agent Tesla screenshot
Agent Tesla
agenttesla trojan rat stealer
Agent Tesla is spyware that collects information about the actions of its victims by recording keystrokes and user interactions. It is falsely marketed as a legitimate software on the dedicated website where this malware is sold.
Read More
Ave Maria screenshot
Ave Maria
avemaria stealer trojan rat
Ave Maria malware is a Remote Access Trojan that is also called WARZONE RAT. Hackers use it to control PCs of their victims remotely and steal information from infected PCs. For example, they can remotely activate the camera to take pictures of a victim and send them to a control server
Read More
Azorult screenshot
Azorult
azorult trojan rat
AZORult can steal banking information including passwords and credit card details as well as cryptocurrency. This constantly updated information stealer malware should not be taken lightly, as it continues to be an active threat.
Read More
Crimson RAT screenshot
Crimson RAT
crimson rat trojan
Crimson is a Remote Access Trojan — a malware that is used to take remote control of infected systems and steal data. This particular RAT is known to be used by a Pakistani founded cybergang that targets Indian military objects to steal sensitive information.
Read More
Danabot screenshot
Danabot
danabot trojan stealer
Danabot is an advanced banking Trojan malware that was designed to steal financial information from victims. Out of the Trojans in the wild this is one of the most advanced thanks to the modular design and a complex delivery method.
Read More