The Kedi Trojan is a newly discovered malware that is being distributed worldwide that uses Gmail to communicate with the hacker-controlled servers. The code analysis reveals that it is a complex computer virus that can be used in many infiltration scenarios. Our article provides an overview of the Trojan operations and it also may be helpful in attempting to remove the Trojan.
|Short Description||The Kedi Trojan is a utility malware that is designed to silently infiltrate computer systems, active infections will spy on the victim users.|
|Symptoms||The victims may not experience any apparent symptoms of infection.|
|Distribution Method||Freeware Installations, Bundled Packages, Scripts and others.|
|Detection Tool|| See If Your System Has Been Affected by Kedi Trojan |
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|User Experience||Join Our Forum to Discuss Kedi Trojan.|
Kedi Trojan – Distribution Methods
The Kedi Trojan is a new weapon used by computer criminals to infect users all around the world. At the moment the primary method of distribution is the use of phishing email messages. The captured samples indicate that the malicious users behind it attempt to confuse the recipients into believing that they have received a legitimate message from a well-known company. The goal is to deliver an infected payload to the users. They can be either attached directly or linked in the body contents.
In addition the payload files can also be uploaded to hacker-created sites. They are made by taking the web design elements of well-known portals or vendors and uploading the files to it.
There are two main types of malicious payloads that are being used to the Kedi Trojan:
- Infected Software Installers — The hackers can take the legitimate setup files of famous applications and modify them to include the Kedi Trojan code. In this particular case the attacks target a popular system utility.
- Malicious Documents — The criminals can take advantage of macro-infected files. They are usually documents of different types (rich text files, documents, spreadsheets and presentations). Once they are opened by the victims a notification prompt will appear asking them to enable the built-in macros. Once this is done the infection will follow.
The infected files can also be spread on file sharing networks such as BitTorrent trackers where pirate content is usually spread. During the coordination of the attacks the criminals can also opt to utilize malicious scripts.They can be spread onto ad networks with the intent of redirecting more users to the malicious sites where the Kedi Trojan is hosted. Such behavior warrants the use of a lot of techniques and produced code — banners, pop-ups, redirects and in-line hyperlinks.
Advanced infections can be done via browser hijackers as well. They are dangerous plugins made for the most popular web browsers — Mozilla Firefox, Google Chrome, Internet Explorer, Microsoft Edge and Opera. The various strains are then uploaded to the associated repositories. The posted descriptions aspire to coerce the victim users into downloading the malicious samples to their computers, often they are accompanied by fake developer credentials or user reviews. Once they are installed on the infected machines the built-in behavior pattern will be triggered. Similar threats like this one are programmed to redirect the victim users to a hacker-controlled page by changing the default settings — home page, search engine and new tabs page. Once this is done the malicious engine will proceed with the Kedi Trojan execution.
Kedi Trojan – Detailed Description
One of the distinct characteristics of the Kedi Trojan is the way it has been created. The hackers behind it have modeled it to pose as a legitimate utility. This is done by including counterfeit signatures in the executable files (reading “Citrix NetScaler Unified Gateway”) and having a hijacked a legitimate looking splash screen. When starting up the file it will show a loading status which raises no suspicion when run.
During its initialization the analysts have detected that it contains a stealth protection functionality. This is executed by a component that scans for the presence of applications that can interfere with the virus execution. The list includes anti-virus solutions, sandbox environments or virtual machine hosts. If configured so the engine can block the real-time engines or delete the software altogether. In certain cases the virus samples can delete themselves if they are unable to perform this step. This behaviour is programmed in order to hide the infection from being noticed by the system administrators.
Following the successful infection of the host computers the Kedi Trojan will install itself in the application data folder belonging to Adobe. This shows that criminals have implemented a masquarade feature that implants the threat in a predefined location. The main module will be accompanied by a lock file (with the .lck extension) which is as marker that shows processes and applications not to interact with it. The newly created folders can also be used for utility storage of log files, screenshots and other useful output.
The code analysis shows that the Kedi Trojan is also capable of modifying certain Windows Registry entries.
It can create entries belonging to itself or modify existing ones belonging to the user-installed applications or to the operating system itself. This can lead to the inability to start certain applications or services, in addition the victims will experience performance issues. The configuration file of the Trojan is stored in a protected form that is decrypted on-the-fly as the malware is run.
The configuration file can be fine tuned to deliver specific customized variants according to local conditions. This means that the malicious engine can also engage a thorough data harvesting module. Similar threats like this one can extract strings that can be grouped into two main types:
- Personal Information — This data set can directly expose the identity of the victims. The collected strings include the person’s name, address, phone number, interests, location and any stored account credentials.
- Campaign Metrics — The engine can be used to hijack data that can be useful to the hacker operators. The data harvesting module can generate a report of the hardware component and certain user-set settings.
Kedi Trojan – Trojan Operations
Once all prior components have finished execution the Trojan infection will be triggered. It contains many advanced features that are not found in other common threats. This gives the analysts the assumption that custom code has been implemented by the hacker operators.
The Kedi Trojan connects to a hacker-controlled server using a secure connection however instead of using a common channel (such as IRC, Telnet or something else) it uses a Gmail-based back end. The client machine connects to a Gmail account viathe basic HTML web interface using an automated behavior pattern. This is an interesting approach as it has two major advantages. The first one is that Gmail access should not raise suspicion during network analysis. The creation of Google accounts can also be automated to a certain degree which can supply a steady stream of different accounts.
The exact mechanism follows a predefined model that follows a step-based behaviour:
- The Trojan module establishes the connection to the Gmail account va the built-in credentials.
- Using the Gmail connection the host sends a report to the hackers signaling them about the newly made infection.
- Using an automated approach the Trojan module will refresh the inbox checking for new commands and instructions sent by the hackers.
The successful installation of this module can be used to deliver additional threats. This is especially dangerous if done with ransomware or banking Trojans. Triggering the Trojan’s capabilities can also allow the hackers to generate screenshots of the active user’s activities either manually or automatically. If custom code is used the attackers can generate malicious pop-ups that can be used in carrying out scams. Trojans like this one can lead to the initialization of keyloggers — automated software that can grab certain strings that falls into a specific category. They can sense when users enter account credentials into login prompts and other related fields.