So that’s why it’s free..

Summary

A Russian-aligned hacker group has exploited vulnerabilities in WinRAR to infiltrate businesses and steal data. The attack targets a specific flaw (CVE 20258088) in how WinRAR handles alternative data streams, allowing attackers to hide malicious files in RAR archives. The video also highlights Threat Locker’s endpoint protection as a defense against such attacks, explaining how it blocks suspicious activities. Finally, it touches on the broader challenges of securing software and the importance of sanitizing file handling to prevent exploits like these, emphasizing the role of memory corruption and logic issues in cybersecurity.

Takeaways

• 😀 Hackers are exploiting vulnerabilities in WinRAR, the file compression software, with the help of a Russian-aligned group called Romcom.
• 😀 WinRAR's vulnerabilities, including CVEs, have been exploited in real-world cyberattacks targeting businesses to steal money.
• 😀 WinRAR uses a file format called RAR, which can store files more compactly, but these formats are prone to security issues due to complex file systems and compression logic.
• 😀 The CVE being discussed, CVE-20258088, affects WinRAR's handling of Alternative Data Streams (ADS), a feature of the NTFS file system in Windows.
• 😀 Alternative Data Streams (ADS) are used to store metadata about files, but hackers have used them to hide malicious files and obfuscate their activity.
• 😀 The attack exploits a 'directory traversal' vulnerability where malicious files are written outside the expected folder, enabling attackers to place malicious files higher up in the system (e.g., app data).
• 😀 Hackers are hiding malicious DLL files (e.g., MS Edge.dll) in temporary system folders, which are then loaded by the system to execute malicious code.
• 😀 This is a logic/sanitization issue rather than a memory corruption bug, which makes it easier for attackers to exploit without needing sophisticated memory attacks.
• 😀 A previous CVE (2023-38831) showed similar vulnerabilities in WinRAR, such as issues handling files with the same name that could lead to script execution.
• 😀 While Rust programming is often touted for its safety, this type of vulnerability (logic/sanitization issues) could still exist, as Rust doesn’t guarantee protection against such issues in its current ecosystem.

Q & A

What is WinRAR, and how is it typically used?

WinRAR is a file compression software that allows users to compress and decompress files. It is commonly used to reduce the size of files for easier storage and sharing, especially when dealing with large files.

What does CVE stand for, and why is it important in the context of this video?

CVE stands for Common Vulnerabilities and Exposures. It is a system used to publicly identify and catalog security vulnerabilities. In the context of this video, several CVEs in WinRAR are being exploited by hackers to gain access to systems.

What is the role of alternative data streams (ADS) in this vulnerability?

Alternative data streams (ADS) are a feature of the NTFS file system that allows additional metadata to be stored alongside regular file data. In this vulnerability, attackers use ADS to hide malicious content in RAR files, making it harder to detect.

What is a directory traversal vulnerability, and how does it work in this case?

A directory traversal vulnerability allows attackers to move up and down the directory structure on a system. In this case, by using directory traversal patterns, attackers are able to place malicious files outside the intended RAR extraction folder, potentially compromising the system.

What is the significance of the MS Edge DLL file in this attack?

The MS Edge DLL file is part of the attack because once it is placed in a system's temp folder and executed, it loads malicious content when the Microsoft Edge browser runs, allowing the attacker to execute further commands and potentially steal information.

How does WinRAR handle file paths, and why does this create a security risk?

WinRAR handles file paths by extracting files from compressed archives to specific directories. However, it doesn't properly sanitize file paths, which allows attackers to manipulate paths using directory traversal techniques to place files in insecure locations.

Why is this vulnerability particularly dangerous compared to memory corruption vulnerabilities?

This vulnerability is a logic or sanitization issue rather than a memory corruption problem. It is easier for attackers to exploit since they don't need to manipulate memory or require complex conditions. They can simply craft the file paths to inject malicious content.

What role does Threat Locker play in defending against these kinds of attacks?

Threat Locker is an endpoint protection platform designed to block hackers from gaining access to a network. It uses zero-trust security models to block suspicious activities and provides features like ring fencing to limit the scope of potential exploits.

How do the attackers use the alternative data streams to obfuscate their malicious files?

The attackers use ADS to hide malicious files within a seemingly normal RAR file. They place fake or irrelevant data streams alongside legitimate files, which confuses the system and hides the true intent of the malicious payload.

Why does the video suggest that Rust wouldn't necessarily fix this particular WinRAR vulnerability?

Rust, despite its strong memory safety features, wouldn’t have necessarily prevented this logic or sanitization vulnerability. The issue lies in handling file paths and directory structures, which Rust wouldn’t automatically fix, as it doesn’t address logic flaws in code design.