Threats Tagged 'agenttesla'

Cruciferra is a sophisticated crypter service utilized by multiple unrelated cybercriminal threat clusters to deliver remote access trojans and infostealers. Written in Mono, it employs extensive defense-evasion capabilities including indirect system calls, API unhooking, BYOVD-based EDR tampering, privilege escalation, and customized Process Ghosting for payload execution. The service features over 90 variations of cryptographic functions to obfuscate data and payloads, complicating static analysis and signature-based detection. Cruciferra was first advertised in fall 2025 with pricing tiers ranging from $450 to $2000 monthly. It has been observed in campaigns delivering various malware families including zgRAT, AgentTesla, AsyncRAT, XLoader, XWorm, Phantom Stealer, Formbook, and Remcos, primarily targeting financial services, healthcare, and government entities through opportunistic email-based attacks.

During June 2026, multiple infostealer families including Remus, ACRStealer, LummaC2, and Vidar were distributed through SEO poisoning techniques, disguised as illegal software such as cracks and keygens. Attacks utilized EXE files (84.5%) and DLL side-loading (15.5%) methods, with distribution primarily through Mediafire, Mega, and cloud storage platforms. Microsoft Corporation was the most frequently impersonated entity. MacOS environments were targeted through ClickFix techniques and malicious Bash scripts, with one variant dynamically obtaining C2 addresses via Polygon smart contracts. Email-based campaigns distributed AgentTesla and DarkCloud through compressed attachments, with both variants exfiltrating data via SMTP. The stolen credentials pose significant risks for dark web trading and secondary attacks.

This analysis covers infostealer distribution trends observed during May 2026, based on automated collection systems and diagnostic logs. Distribution occurred primarily through illegal software disguised as cracks and keygens, as well as email campaigns. ACRStealer, Remus, and LummaC2 were most prevalent, with distribution via domains including Mediafire and AWS S3 buckets. Microsoft was the most impersonated company, followed by Auslogics and NVIDIA. EXE files represented 78.9% of execution types, while DLL side-loading accounted for 21.1%. macOS environments saw ClickFix techniques and malicious Bash scripts, with 142 scripts and 12 C2 domains identified. Email campaigns distributed AgentTesla and DarkCloud. Remus showed significant growth, comprising 36% of distributions. LummaC2 remained the most prevalent overall variant.

In March 2026, trojans represented 21% of attachment-based threats, while phishing attacks using fake pages dropped from 42% to 15% month-over-month. Script-based malware increased significantly, with HTML at 14% and JavaScript at 11%. Compressed files including ZIP (14%), RAR (8%), and 7Z (5%) were common distribution methods. Document-based threats utilized PDF (13%), XLS (5%), and DOCX (2%) files. Attackers impersonated courier services like FedEx and DHL, as well as financial institutions including Hana Bank and Woori Bank. Distribution methods included HTML scripts and PDF hyperlinks leading to credential-stealing pages. Notable malware families included RemcosRAT and AgentTesla, with command-and-control infrastructure utilizing Telegram API tokens and external mail servers for data exfiltration.