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 Bloktd℠, 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
Ransomware Trends & Data Insights: July 2026
INC Ransom was the most active threat group in July, while activity remained relatively distributed among multiple threat groups, with 19 unique groups observed throughout the month. Alongside INC Ransom, Qilin, Global Secret Group, Anubis, and DragonForce rounded out the five most active threat groups observed in July. Several emerging threat actors were also observed during the month, including Booba Team, Settra, and Global Secret Group.
Figure 1. Activity from the top 3 threat groups in July 2026
Throughout the month, analysts at Arete identified several trends behind the threat actors perpetrating cybercrime activities:
In July 2026, Global Secret Group emerged as a new threat actor, leveraging the leaked LockBit 3.0 (LockBit Black) source code. Although the group began operations in June 2026, it quickly accumulated a substantial number of victims on its data leak site (DLS). The group operates through TOR-based negotiation portals and qTox communications. Notably, its DLS provides step-by-step guidance on purchasing Bitcoin, including references to Coinbase and Binance, demonstrating a streamlined, victim-focused extortion process designed to simplify ransom payments.
Similar to Fulcrumsec, the recently emerged Settra ransomware group appears to leverage AI-driven analysis of stolen data, publishing detailed and highly structured victim reports on its DLS. Additionally, a potential EDR-disabling tool, edr_blind.exe, was identified in multiple cases, suggesting a focus on defense-evasion capabilities.
With the continuation of the FortiBleed campaign, researchers have now identified compromised FortiGate credentials being leveraged by both the INC and Lynx ransomware operations. Analysis revealed direct operational links between the groups, including shared ransomware infrastructure and overlap between FortiBleed victims and ransomware targets. The operators are also incorporating AI to enhance various stages of the attack lifecycle and increase operational efficiency and scale. Notably, Arete also observed an INC ransomware intrusion leveraging FortiBleed-derived access in July, reinforcing the campaign's role as a precursor to ransomware deployment.
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Arete Internal
Podcast
Cyber Campfire: June Threat Trends & Insights
In this episode of Arete’s Cyber Campfire podcast, our Threat Intelligence Team discusses trends, statistics, and emerging threat actors from June 2026. Tune in for firsthand insights on today’s threat landscape that can enhance your approach to cyber risk.
Article
Current: Misconfigured Server Reveals Multiple Phishing Campaigns
Researchers uncovered three Microsoft 365 phishing campaigns after discovering a misconfigured HTTP server that exposed a threat actor’s phishing tools, configurations, victim logs, and operational infrastructure. The investigation revealed two operators using custom Evilginx-based adversary-in-the-middle (AiTM) phishing frameworks to steal authentication sessions and bypass MFA protections. A third operator abused Microsoft’s OAuth Device Code flow by tricking victims into completing authentication through Microsoft’s legitimate login process, allowing attackers to obtain valid access and refresh tokens without stealing passwords. The largest campaign compromised at least 218 victims across 12 countries, primarily targeting corporate Microsoft 365 accounts, with refresh tokens enabling persistent access. Researchers also identified the use of remote management tools for maintaining access, AI-assisted development of phishing tooling, and links to broader Phishing-as-a-Service (PhaaS) ecosystems, highlighting how commodity frameworks and automation are lowering the barrier for sophisticated identity-based attacks.
What’s Notable and Unique
The campaigns demonstrate the continued shift from traditional credential theft to identity- and token-based compromise, in which attackers target authentication sessions, cookies, and OAuth tokens rather than relying solely on password theft. By obtaining valid authentication artifacts, attackers can access Microsoft 365 environments while bypassing conventional MFA protections.
The use of Evilginx-based AiTM frameworks highlights how publicly available phishing tools have evolved into effective MFA-bypass platforms. These frameworks proxy legitimate login pages, capture authenticated sessions, and allow attackers to reuse valid sessions without requiring victims’ credentials again.
The OAuth Device Code flow abuse represents a different attack method, in which attackers leverage a legitimate Microsoft authentication mechanism to obtain tokens after victims approve the request. This approach bypasses password theft entirely by abusing trusted authentication workflows.
The exposed infrastructure provided insight into attacker operations, including phishing configurations, victim tracking data, remote administration tools, and evidence of AI-assisted development. The findings demonstrate how phishing ecosystems now provide reusable tooling and automation that reduce the technical expertise required to conduct large-scale identity attacks.
Analyst Comments
These Microsoft 365 phishing campaigns demonstrate the ongoing evolution of identity-focused attacks, as adversaries increasingly target authentication sessions, tokens, and legitimate cloud authorization mechanisms to bypass traditional security controls. The combination of AiTM phishing, OAuth abuse, remote management tools, and PhaaS infrastructure enables threat actors to maintain persistent access while blending into legitimate cloud activity.
The growing availability of phishing frameworks and AI-assisted attack development highlights the need for continuous identity security improvements beyond traditional phishing defenses. Arete recommends that organizations strengthen identity monitoring, adopt phishing-resistant MFA where possible, review OAuth application permissions, monitor token activity, and implement conditional access policies to detect and restrict suspicious Microsoft 365 authentication behavior. Security teams should also monitor post-compromise indicators such as abnormal mailbox access, suspicious application consent, unauthorized remote tools, and unusual sign-in activity.
Sources
One Misconfigured Server, Three Active Campaigns: Full exposure of three AiTM Phishing Operators
Misconfigured Server Reveals Three Evilginx Phishing Operations Targeting Microsoft 365
Podcast
Digital Forensics Meets the Courtroom: Insights on Expert Witness and Cyber-Related Litigation
In this episode of Bytes of Insight, host Vinny Sakore and special guest Dr. Bruce Hartley, Managing Director and Co-Founder of Advisory Services at Arete, discuss the evolving role of digital forensics and expert witness work in cybersecurity litigation. Tune in for firsthand insights on how Arete conducts post-breach investigations, what it takes to undergo cross-examination on the stand, and how emerging threats like AI-driven social engineering and third-party breaches are reshaping the advisory landscape.