Quasar RAT

Quasar is a very popular RAT in the world thanks to its code being available in the open-source. This malware can be used to remotely control the victim’s computer.

Type
Trojan
Origin
Unknown
First seen
1 January, 2015
Last seen
13 July, 2020
Global rank
15
Week rank
7
Month rank
8
IOCs
2360

What is Quasar RAT?

Quasar is a remote access trojan is used by the attackers to take remote control of infected machines. It is written using the .NET programming language and available to a wide public as an open-source project, making it a popular RAT that was featured in a number of attacks.

General description of Quasar RAT

Quasar RAT was first discovered in 2015 by security researchers, who, at the time, speculated that this RAT was written by an in-house development team after performing the analysis of a sample. Quasar is an evolution of an older malware called xRAT and some of its samples can carry out as much as 16 malicious actions.

Over the course of its lifetime, the malware has been updated several times, improving its overall functionality. The last version of the malware which was developed by the original author is v. 1.3.0.0. It was released in 2016. Since that time several third parties have adapted the RAT and issued their own version, both minor and major with the last major version being v. 2.0.0.1.

The RAT we are reviewing today consists of two main components – the server-side component and the client-side component. The server is equipped with a graphical user interface and it is used for managing connections with the client-side programs. The server-side component is also utilized to build malware samples which are eventually delivered to potential victims. Malware user has an option to select attributes and customize the executable to fit the needs of the attacker.

The functionality of the resulting malware includes remote file management on the infected machine, registry alterations, recording the actions of the victim, establishing remote desktop connections and more.

It should be noted that Quasar execution can unfold completely silently, thus, once the victim downloads and launches the client, usually delivered in a document via email, it can stay active for a long period of time, stealing data and giving the hacker control over the infected PC. The malware does generate a process that can be discovered using the Windows Task Manager or a similar application, but active user actions are required to discover Quasar trojan presence on a machine.

As far as creators of this malware are concerned, the group of people or a person behind the original version of this malware managed to remain anonymous. The little known information that we do have does not go beyond the name of the GitHub page author which states simply “quasar”.

As evident from the description on the “official” Quasar GitHub page, this malware is presented as a legitimate remote administration program, which is clearly misleading. In fact, Quasar was featured in an attack aimed at the US government early in 2017. Later the same year another wave of attacks using this malware occurred, this time targeting the private sector.

Quasar RAT malware analysis

The execution process of this malware can be viewed in a video recorded in the ANY.RUN malware hunting service, allowing to take a look at how the contamination process unfolds.

process graph of the quasar stealer execution Figure 1: Displays the lifecycle of Quasar in a visual form, as shown on the graph generated by ANY.RUN.

text report of quasar analysis Figure 2: Shows a customizable text report generated by the ANY.RUN malware hunting service.

Quasar RAT execution process

Quasar execution is pretty straightforward but can vary in minor details from sample to sample. In a given example, Quasar was dropped from a Microsoft Office file. The dropped file changed the registry value to make itself run with every operating system start, checked for external IP and also copied itself at another location. After all these steps, the malware started the main malicious activity - collecting information about the operating system and waiting for commands from the C2 server.

How to avoid infection by Quasar?

Quasar trojan writes itself into scheduled tasks and uses registry keys to achieve persistence, allowing the malware the run every time a machine is started. The persistence method is chosen based on user privileges. As such, if the user has admin rights, the malware uses schtasks to create a scheduled task which launches after a user logs on with the highest run level. If admin rights are lacking, then the scheduled task can only go as far as to add a registry value which is configured in the client builder and added to the current path as the startup program.

Distribution of Quasar RAT

Just as most of the other RATs, Quasar is distributed in email spam campaigns that carry the malware’s loader. The loader is embedded in a malicious file attachment which usually carries a name designed to trick the user into thinking that he or she is receiving some sort of a document. Sometimes these files will have a double extension such as docx.exe. This is done to trick the victim into thinking that the attached file is harmless. Of course, once opened, such files start a command prompt rather than Microsoft Office.

How to detect Quasar RAT using ANY.RUN?

ANY.RUN uses Suricata IDS rule sets so if malware trying to communicate with C&C servers it will be detected. To look at what threats were detected just click on the "Threats" section of the "Network" tab.

quasar network threats Figure 3: Quasar network threats

Conclusion

Quasar trojan is a powerful open-source malware equipped with a robust persistence mechanism and a complete feature set of malicious capabilities. Being available to anybody with programming knowledge, Quasar became a widely used RAT which was even featured in an attack targeted at the American government.

However, unlike other more advanced Trojans, Quasar RAT does not have extremely sophisticated anti-analysis features, which makes setting up robust cyber-defense an easier task, especially when using malware hunting services like ANY.RUN to simplify and streamline the research process.

IOCs

IP addresses
208.95.112.1
193.161.193.99
88.198.193.213
185.140.53.6
184.73.165.106
68.7.77.87
79.134.225.5
194.5.97.121
3.23.201.37
58.158.177.102
208.95.112.1
37.223.208.94
68.48.42.187
172.67.75.176
86.144.71.246
82.82.92.191
95.44.73.155
139.162.111.226
79.134.225.92
84.194.102.183
Hashes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isns.net
Bigpp1234-23204.portmap.host
DannyJanny-46342.portmap.io
DeeJay140-28261.portmap.io
Alais-63967.portmap.host
Alais-59568.portmap.host
hakanhaxi-57335.portmap.host
gemaco4921-51956.portmap.host
Mamae8025-63645.portmap.host
Cahya-38482.portmap.host
Rotsu69-52689.portmap.host
MorningSTAR000-42786.portmap.host
MorningSTAR000-44638.portmap.host
AutoTpoxicity-48915.portmap.host
imrooter-58068.portmap.host
unlock-27800.portmap.host
iamhack3r-37791.portmap.host
stevelong-21798.portmap.io
lbsparks-29180.portmap.host
vikolan294-55965.portmap.io

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