Quasar RAT

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

Type
Trojan
Origin
Unknown
First seen
1 January, 2015
Last seen
20 May, 2022
Global rank
13
Week rank
10
Month rank
10
IOCs
7877

What is Quasar RAT?

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

General description of Quasar RAT

Quasar RAT was first discovered in 2015 by security researchers, who, at the time, speculated that an in-house development team wrote this RAT after performing the analysis of a sample. However, Quasar is an evolution of an older malware called xRAT, and some of its samples can carry out as many 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 the original author developed, is v. 1.3.0.0. It was released in 2016. Since then, 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 Quasar 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 Quasar client-server architecture is also utilized to build malware samples which are eventually delivered to potential victims. Malware users can select attributes and customize the executable to fit the attacker's needs. The Quasar client and server run on different OSs including all Windows versions.

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. All of the data including requests are sent to the host server with the user-agent strings.

It should be noted that Quasar's execution can unfold completely silently. Thus, once the victim downloads and launches the Quasar 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's 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. As a result, the little-known information that we do have does not go beyond the name of the GitHub page author, which states “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, 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 perform analysis of 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

Based on the analysis, Quasar execution is pretty straightforward but can vary in minor details from sample to sample. The RAT's user-agent strings fake various processes such as a browser running on Windows. In the given example, Quasar was dropped from a Microsoft Office file. Then, the dropped file changed the registry value to run with every operating system start, checked for external IP, and 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. Quasar allows malware users to collect host system data.

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. If the user has admin rights, the malware uses schtasks to create a scheduled task that 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 adding a registry value configured in the client builder and added to the current path as the startup program. The best way to avoid infection is for cybersecurity specialists gt to know various user-agent strings that exist in their network, and identify suspicious user-agent strings.

Distribution of Quasar RAT

Like most other RATs, for example Crimson RAT or Orcus RAT, 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 they are receiving some sort of a document. Sometimes these files will have a double extension such as docx.exe. Again, 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 tries 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
66.254.114.41
3.22.53.161
208.95.112.1
140.82.121.4
138.197.189.80
208.91.197.91
45.134.140.167
3.124.67.191
3.13.191.225
3.22.30.40
18.197.239.109
3.66.38.117
45.131.109.121
104.26.6.150
18.189.106.45
3.140.223.7
147.185.221.212
3.141.177.1
3.17.7.232
3.125.209.94
Hashes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api.adinplay.com
googleapis2m.duckdns.org
googleapis2.duckdns.org
susur2334.duckdns.org
2.tcp.ngrok.io
WindowsAuthentication324-49629.portmap.host
anteph.org
booking.msg.bluhotels.com
booking.msg.bluhotels.com
ticket.ipv10.eu
3jkpvk2m8y.dattolocal.net
chromedriver.chromium.org
7.tcp.eu.ngrok.io
lcdn.tsyndicate.com
gist.github.com
device-local-3193b8ff-0889-41c5-8fd6-67066f88b277.remotewd.com
optibet.ladesk.com
majul.com
eceda.duckdns.org
scca.duckdns.org

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 the 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