Malware Analysis Report - LockBit Ransomware v4.0

In this blog post, I’m going over my analysis for the latest variant of LockBit ransomware - version 4.0. Throughout this blog, I’ll walk through all the malicious functionalities discovered, complete with explanations and IDA screenshots to show my reverse engineering process step by step. This new version of LockBit 4.0 implements a hybrid-cryptography approach, combining Curve25519 with XChaCha20 for its file encryption scheme.

This version shares similarities with the older LockBit Green variant that is derived from Conti ransomware. While the multi-threading architecture seems more streamlined than previous versions, it still delivers an encryption speed that outpaces most other ransomware families.

As always, LockBit is still my most favorite malware to look at, and I certainly enjoyed doing a deep dive to understand how this version works.

This Google Threat Intelligence Group report presents an analysis of detected 2024 zero-day exploits.

Google Threat Intelligence Group (GTIG) tracked 75 zero-day vulnerabilities exploited in the wild in 2024, a decrease from the number we identified in 2023 (98 vulnerabilities), but still an increase from 2022 (63 vulnerabilities). We divided the reviewed vulnerabilities into two main categories: end-user platforms and products (e.g., mobile devices, operating systems, and browsers) and enterprise-focused technologies, such as security software and appliances.

Vendors continue to drive improvements that make some zero-day exploitation harder, demonstrated by both dwindling numbers across multiple categories and reduced observed attacks against previously popular targets. At the same time, commercial surveillance vendors (CSVs) appear to be increasing their operational security practices, potentially leading to decreased attribution and detection.

We see zero-day exploitation targeting a greater number and wider variety of enterprise-specific technologies, although these technologies still remain a smaller proportion of overall exploitation when compared to end-user technologies. While the historic focus on the exploitation of popular end-user technologies and their users continues, the shift toward increased targeting of enterprise-focused products will require a wider and more diverse set of vendors to increase proactive security measures in order to reduce future zero-day exploitation attempts.

Cisco Talos discovered a sophisticated attack on critical infrastructure by ToyMaker and Cactus, using the LAGTOY backdoor to orchestrate a relentless double extortion scheme.

• In 2023, Cisco Talos discovered an extensive compromise in a critical infrastructure enterprise consisting of a combination of threat actors.
• From initial access to double extortion, these actors slowly and steadily compromised a multitude of hosts in the network using a combination of various dual-use remote administration, SSH and file transfer tools.
• The initial access broker (IAB), whom Talos calls “ToyMaker” and assesses with medium confidence is a financially motivated threat actor, exploits vulnerable systems exposed to the internet. They deploy their custom-made backdoor we call “LAGTOY” and extract credentials from the victim enterprise. LAGTOY can be used to create reverse shells and execute commands on infected endpoints.
• A compromise by LAGTOY may result in access handover to a secondary threat actor. Specifically, we’ve observed ToyMaker handover access to Cactus, a double extortion gang who employed their own tactics, techniques and procedures (TTPs) to carry out malicious actions across the victim’s network.

In this two-part series, SpiderLabs explores the malicious traffic associated with Proton66, revealing the extent and nature of these attacks.

Mass scanning and exploit campaigns targeting multiple sectors
Starting from January 8, 2025, SpiderLabs observed an increase in mass scanning, credential brute forcing, and exploitation attempts originating from Proton66 ASN targeting organizations worldwide. Although malicious activity was seen in the past, the spike and sudden decline observed later in February 2025 were notable, and offending IP addresses were investigated.

AS198953, belonging to Proton66 OOO, consists of five net blocks, which are currently listed on blocklists such as Spamhaus due to malicious activity. Net blocks 45.135.232.0/24 and 45.140.17.0/24 were particularly active in terms of mass scanning and brute force attempts. Several of the offending IP addresses were not previously seen to be involved in malicious activity or were inactive for over two years. For instance, the last activities reported in AbuseIPDB for the IP addresses 45.134.26.8 and 45.135.232.24 were noted in November and July 2021, respectively.

Learn how a convincing Google spoof used a DKIM replay attack to bypass email security and trick users with a fake subpoena. A real-world phishing example you need to see.

Since October 2024, Microsoft Defender Experts has observed and helped multiple customers address campaigns leveraging Node.js to deliver malware and other payloads that ultimately lead to information theft and data exfiltration.

In March 2025, our team found a suspicious mach-O file named wsus. Read the full analysis on its likely origins, target users, and observed functionality.

After the release of the Secure Annex ‘Monitor’ feature, I wanted to help evaluate a list of extensions an organization I was working with had configured for monitoring. Notifications when new changes occur is great, but in security, baselines are everything!

To cut down a list of 132 extensions in use, I identified a couple extensions that stuck out because they were ‘unlisted’ in the Chrome Web Store. Unlisted extensions are not indexed by search engines and do not show up when searching the Chrome Web Store. The only way to access the extension is by knowing the URL.

In February 2025, the cybersecurity community witnessed an unprecedented leak that exposed the internal operations of Black Basta.

As large language models (LLMs) become more advanced and are granted additional capabilities by developers, security risks increase dramatically. Manipulated LLMs are no longer just a risk of...

Key Takeaways The threat actor gained initial access by a fake Zoom installer that used d3f@ckloader and IDAT loader to drop SectopRAT. After nine days of dwell time, the SectopRAT malware dropped …

Lucid is a sophisticated Phishing-as-a-Service (PhaaS) platform operated by Chinese-speaking threat actors, targeting 169 entities across 88 countries globally. With 129 active instances and 1000+ registered domains, Lucid ranks among prominent PhaaS platforms, alongside Darcula and Lighthouse.
Its scalable, subscription-based model enables cybercriminals to conduct large-scale phishing campaigns to harvest credit card details for financial fraud. The platform employs an automated attack delivery mechanism, deploying customizable phishing websites distributed primarily through SMS-based lures. To enhance effectiveness, Lucid leverages Apple iMessage and Android’s RCS technology, bypassing traditional SMS spam filters and significantly increasing delivery and success rates.
Lucid incorporates advanced anti-detection and evasion techniques, such as IP blocking and user-agent filtering, to prolong the lifespan of its phishing sites. Additionally, it features a built-in card generator, enabling threat actors to validate and exploit stolen payment data efficiently. Given its advanced infrastructure and persistent activity, Lucid poses a significant and ongoing cyber threat. Its operations underscore the growing reliance on PhaaS platforms to facilitate payment fraud and financial cybercrime, necessitating heightened vigilance and proactive mitigation efforts.

Next.js is an open-source web framework built by Vercel that powers React-based apps with features like server-side and static rendering. Recently, a critical vulnerability (CVE) was disclosed that lets attackers bypass middleware-based authorization checks. The issue was originally discovered and analyzed by Rachid Allam (zhero). In this blog, we’ll break down the vulnerability and walk through their research and will create a Nuclei template to help you detect it across your assets.

Discover technical analysis of GorillaBot, a new malware variant based on the original code of the Mirai botnet.

orums as part of our Threat Discovery Process.
Designed to target Windows systems, this ransomware employs advanced encryption techniques and appends a unique file extension to compromised files. Its stealthy evasion tactics and persistence mechanisms make detection and removal challenging. This highlights the need for proactive cybersecurity measures and a robust incident response strategy to safeguard data integrity and minimize breach risks.

Target Technologies: Windows
Target Geography: France, USA.
Target Industry: Government, Manufacturing, Pharma.
Encrypted file extension: .vanhelsing
Observed First: 2025-03-16
Threat actor Communication mode: Tor

Over 100 auto dealerships were being abused compliments of a supply chain attack of a shared video service unique to dealerships. When active, the attack presented dealership visitors with a ClickFix webpage which led to a SectopRAT malware.

Discover how the ClickFix social engineering attack exploits human psychology to bypass security. Learn how hackers use this tactic and how to protect against it.

Attacks using this ransomware have displayed consistent TTPs and grown steadily since 2023.

A newly discovered global cyber threat is rapidly expanding, infecting tens of thousands of internet-connected devices to launch powerful cyberattacks.

Key Takeaways The intrusion began with the exploitation of CVE-2023-22527 on an exposed Windows Confluence server, ultimately leading to the deployment of LockBit ransomware across the environment.…