Article
Browser Threats Evolve to Distribute Malware Through OneDrive and Microsoft Teams
Arete Analysis
Cyber Threats
Cybersecurity Trends
Threat researchers published an update to a technique that allows threat actors to evade common security measures by injecting malware through web browsers. Using social engineering techniques, threat actors can execute malicious code using Microsoft OneDrive and Teams applications. The new technique, referred to as browser cache smuggling, is the latest in attacks using web browsers to evade many common security measures, including endpoint detection and response (EDR) solutions.
What’s Notable and Unique
To enhance efficiency, modern browsers cache static files (such as photos and JavaScript), and threat actors take advantage of this by hiding malicious dynamic link library (DLL) files on a website under the guise of harmless content, such as pictures.
Threat actors then use social engineering to get victims to run a PowerShell command that finds the cached DLL and relocates it to a high-risk directory, like the localappdata directories in OneDrive or Microsoft Teams. The threat actors then use OneDrive and Teams to load and execute the malicious content using a technique called DLL proxying.
Analyst Comments
Threat actors have historically injected malicious code through web browsers and, more recently, leveraged social engineering techniques to get users to run malicious PowerShell commands. They then separately used DLL proxying to load malicious content. This newly published technique enables threat actors to combine these two capabilities. The combination enables threat actors to move further through an attack while evading defenses. It is likely that additional ransomware and extortion groups will adopt this new technique to improve the success of their operations.
Threat actors’ increased use of social engineering to get users to execute malicious code demonstrates the importance of limiting user access to scripting engines. General users likely do not need PowerShell, Python, Docker, or similar tools enabled on their desktops. Role-based application control is critical to preventing the effectiveness of this and similar techniques currently used by ransomware groups. To effectively detect the use of the browser cache to enable this new technique, organizations should consider specific EDR detections for any application except a browser accessing the browser cache. At Arete, these types of detections are applied through Arete BloktdSM, our next-generation threat identification and protection service that enhances EDR tools with custom threat detection rules that act autonomously in seconds to proactively identify threats and prevent cyberattacks.
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Article
CMS Vulnerability Leads to ClickFix Campaign
Threat actors compromised at least 700 education and technology websites in a recent ClickFix campaign by exploiting a critical SQL injection flaw (CVE-2026-26980) in the Ghost content management system (CMS). Adversaries combined the vulnerability with the ClickFix social engineering tactic to steal admin keys and inject a malicious JavaScript that delivers a fake Cloudflare or CAPTCHA verification pop-up, tricking victims into copying and pasting a malicious command into their systems.
What’s Notable and Unique
Rather than targeting the end user first, this campaign is unique in its initial exploitation of the system, followed by social engineering attempts. This hybrid attack style is likely being leveraged to bypass traditional defenses.
This recent campaign also highlights how trusted web properties can be weaponized at scale and coupled with unpatched CMS vulnerabilities. Rather than using the CMS compromise to perpetrate a single attack, threat actors turned it into a supply-chain attack that ultimately affected over 700 trusted websites.
Analyst Comments
As network defenders and their tools enhance threat detection capabilities, adversaries increasingly seek methods to bypass these defenses. By combining vulnerability exploitation, social engineering techniques, and staging for ancillary attacks, this campaign successfully bypassed traditional defenses and inflicted significant impact. Defending against hybrid cyberattacks requires comprehensive security controls beyond simply patching vulnerabilities. Organizations should focus on limiting movement within the environment, detecting abuse of trusted applications, and preventing end-user manipulation.
Sources
700+ education and tech websites hijacked in huge ClickFix malware campaign
Under the engineering hood: Why Malwarebytes chose WordPress as its CMS
Think before you Click(Fix): Analyzing the ClickFix social engineering technique
Ghost CMS Vulnerability Exploited to Infect 700 Sites With ClickFix Malware
Article
Threat Actors Leverage Fake JPEG Files for Initial Access
In a recent campaign, researchers observed threat actors using fake JPEG image files as a delivery mechanism to initiate the deployment of additional malicious components. The false JPEG files are typically distributed via phishing emails or other social engineering-based lures, and are actually PowerShell-based malware that deploys a trojanized version of ConnectWise ScreenConnect to establish and maintain persistence in the compromised environment.
What’s Notable and Unique
This campaign leverages JPEG images as the initial lure, where the images are not merely decoys but part of the infection workflow. Victims are typically led to download or open an image that triggers hidden execution logic or redirects them to a payload-delivery sequence that initiates later stages of the intrusion chain.
The attack chain is designed to blend into legitimate environments, making detection more difficult. Execution typically relies on scripted or native Windows components, often including PowerShell or other living-off-the-land binaries, enabling fileless or near-fileless execution and reducing forensic artifacts on disk.
The multistage design ensures that the initial JPEG does not directly contain the full payload but instead triggers retrieval or decryption steps that progressively assemble the final malicious components in memory.
Analyst Comments
This campaign illustrates how threat actors continue to blur the line between legitimate file handling and malicious execution chains, indicating potential overlap with remote management or administrative tooling. The use of JPEG-based staging combined with script-based execution reflects a broader evolution toward a stealth-first intrusion design, in which file formats serve as triggers rather than payload containers.
Sources
OPERATION SILENTCANVAS : JPEG BASED MULTISTAGE POWERSHELL INTRUSION
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