Sunday, July 14, 2024

Hackers Hiding Malware Behind The PNG Images Using Steganography 

The Worok threat infects victims’ computers with information-stealing malware by concealing malware within PNG images with the help of the Steganography technique, which makes it very difficult to detect by malware scanners.

The finding has substantiated one of the most crucial links in the chain of infection of the threat actor as claimed by the experts at Avast. These malicious PNG images are used by threat actors to conceal a payload that facilitates information theft under the guise of being an image.

In the past couple of months, ESET has been revealing details of attacks that Worok has been launching against several high-profile companies and local government agencies in the following regions:-

  • Middle East
  • Southeast Asia
  • South Africa

There are tactical overlaps between Worok and a Chinese threat actor known as TA428 that is believed to be sharing similar tactics.

Compromise Chain

Steganography is a technique that hides scripts within PNG images, such as the compromise series of Worok, which utilizes a C++-based loader which is known as “CLRLoad.”

As of right now, we do not know what vector was used in the initial attack. As part of certain intrusions, the malware was also deployed on Microsoft Exchange Server by exploiting the ProxyShell vulnerability.

A custom malicious kit was then deployed by the attackers using publicly available exploit tools that were available for free. Therefore, the final compromise chain can be summarized as follows:- 

First, CLRLoader is implemented, where simple code is implemented to load the PNGLoader, which is the second stage in the process.

In order to decode the malicious code possessed within the image, the PNGLoad comes in two different variants. While doing so, they launch either the following payloads:-

  • PowerShell script 
  • .NET C#-based

It has been difficult for PowerShell to find the script and they have recently discovered a new malware called DropboxControl, which is spyware that steals information from the system. Provide the threat actor with the ability to upload, download, and run commands contained in specific files.

Malware in PNG Files

When a viewer of an image is opened to view the steganographic code within it, it appears as if the image file is normal.

An image was encoded in a way that allows malicious code to be embedded in the least significant bits of each pixel in the image using a technique known as “least significant bit” (LSB) encoding.

No matter how the third-stage implant is deployed, it is clear that Worok has intelligence-gathering objectives that go beyond simply harvesting files of interest.

Worok attacks have been prompted by tools that are not circulating in the wild. Therefore, it’s likely that these tools are used by the group themselves exclusively to conduct attacks.

Indicators of Compromise

PNG file with steganographically embedded C# payload




Also Read: The Next-Generation Secure Web Gateway (SWG) – What You Need To Know?


Latest articles

mSpy Data Breach: Millions of Customers’ Data Exposed

mSpy, a widely used phone spyware application, has suffered a significant data breach, exposing...

Advance Auto Parts Cyber Attack: Over 2 Million Users Data Exposed

RALEIGH, NC—Advance Stores Company, Incorporated, a prominent commercial entity in the automotive industry, has...

Hackers Using ClickFix Social Engineering Tactics to Deploy Malware

Cybersecurity researchers at McAfee Labs have uncovered a sophisticated new method of malware delivery,...

Coyote Banking Trojan Attacking Windows Users To Steal Login Details

Hackers use Banking Trojans to steal sensitive financial information. These Trojans can also intercept...

Hackers Created 700+ Fake Domains to Sell Olympic Games Tickets

As the world eagerly anticipates the Olympic Games Paris 2024, a cybersecurity threat has...

Japanese Space Agency Spotted zero-day via Microsoft 365 Services

The Japan Aerospace Exploration Agency (JAXA) has revealed details of a cybersecurity incident that...

Top 10 Active Directory Management Tools – 2024

Active Directory Management Tools are essential for IT administrators to manage and secure Active...
BALAJI is an Ex-Security Researcher (Threat Research Labs) at Comodo Cybersecurity. Editor-in-Chief & Co-Founder - Cyber Security News & GBHackers On Security.

Free Webinar

Low Rate DDoS Attack

9 of 10 sites on the AppTrana network have faced a DDoS attack in the last 30 days.
Some DDoS attacks could readily be blocked by rate-limiting, IP reputation checks and other basic mitigation methods.
More than 50% of the DDoS attacks are employing botnets to send slow DDoS attacks where millions of IPs are being employed to send one or two requests per minute..
Key takeaways include:

  • The mechanics of a low-DDoS attack
  • Fundamentals of behavioural AI and rate-limiting
  • Surgical mitigation actions to minimize false positives
  • Role of managed services in DDoS monitoring

Related Articles