Daily Summary
Agent Tesla sample volume reached 61 new samples on 2026-05-10, a slight 8% uptick over the 7-day average of 56. Activity remains stable with no dramatic surge or decline, indicating sustained operational tempo from its distribution networks.
New Samples Detected
Executables dominate with 36 .exe samples, consistent with Agent Tesla’s typical binary-delivery pattern. Notable is the presence of 15 .js files, representing 24% of today’s intake, up from the weekly average of 18%. Single occurrences of ambiguous file types like .93763227 and .tar suggest operators are testing nonstandard extensions to bypass static file filters. A lone .dll sample indicates potential sideloading experiments.
Distribution Methods
The heavy .js component points to phishing emails with JavaScript-based downloaders, likely fetching the main payload from remote servers. The .vbs and .vbe files align with older VBScript variants still in circulation. The .rar and .tar archives suggest compressed payloads used as email attachments or secondary stages. No macro-enabled Office documents were observed today.
Detection Rate
Current Agent Tesla variants show moderate detection rates on major engines (60-75%), with the .53763227 extension sample likely burning through initial scans. The .dll sideloader variant may evade heuristic detection until behavioral analysis is triggered. The .js files are often flagged only after deobfuscation, leaving a window for initial compromise.
C2 Infrastructure
No new C2 servers were identified today, suggesting the current infrastructure of existing IPs and domains remains active. This lack of churn indicates operators favor stability over rapid rotation, though it also signals a potential upcoming migration to avoid IoC exhaustion.
7-Day Trend
Activity remains steady with no directional shift; today’s 61 samples align with the 56-samples-per-day average. The week shows a flat pattern, suggesting neither a ramp-up for a campaign nor a cooling-off period.
Security Analysis
The monoculture of .exe files is fracturing: the mix of .js, .vbs, and archive-based delivery reflects a tactical shift to evade email gateway filters that increasingly block executables. Notably, the .93763227 extension is likely a fragmented executable split across multiple files, a technique used to bypass attachment size limits. Monitoring for split-file downloads in email logs is recommended. Actionable defense: deploy a policy to block all nonstandard extensions at the email gateway unless explicitly whitelisted, and enforce JavaScript execution only from trusted, signed sources.