Daily Summary
Agent Tesla activity remains stable, with 21 new samples identified today, closely aligning with the 7-day average of 22. No significant surge or decline in volume is observed. The lack of new C2 infrastructure suggests a continuation of established campaigns.
New Samples Detected
JavaScript (.js) files continue to dominate the delivery chain, accounting for 13 of the 21 new samples. The remaining samples consist of executable (.exe) files and a single malicious document (.doc). The presence of a file with the non-standard .26413493 extension is notable, likely an attempt to evade basic filtering by using an obscure or randomized file type.
Distribution Methods
The prevalence of .js files indicates ongoing reliance on script-based delivery, commonly distributed via phishing emails with malicious attachments or links. The single .doc file suggests a parallel, lower-volume campaign utilizing macro-enabled documents, while the .exe samples may represent compiled payloads or direct execution of the stealer.
Detection Rate
Current Agent Tesla variants are generally well-detected by major antivirus engines, with a high community detection rate for known hashes. However, the use of obfuscated .js scripts and the anomalous file extension may provide limited, initial evasion against signature-based defenses before behavioral detection triggers.
C2 Infrastructure
No new command-and-control servers were identified today. This indicates operators are likely persisting with existing, resilient infrastructure, possibly using compromised websites or bulletproof hosting to maintain communication channels with infected hosts.
7-Day Trend
Daily sample counts have fluctuated minimally around the 22-sample average this week, indicating consistent, moderate threat actor output without a clear ramp-up or cooling-down phase.
Security Analysis
The continued heavy use of .js files, paired with the appearance of a file with a randomized numeric extension, points to an adaptation in initial access tactics. This contrasts with periods where Agent Tesla heavily utilized ISO or archive files. The numeric extension is a low-sophistication but effective technique to bypass filters looking for common executable extensions. Recommendation: Enhance email and endpoint security to treat files with randomized or unknown extensions, particularly those arriving with .js files, as high-risk. Implement policies to block or sandbox JavaScript execution from untrusted sources, as this remains the primary initial vector for this stealer.