SemanticsAV Intelligence Report

Executive Verdict Summary

The SemanticsAV Engine has identified this file as MALICIOUS with 100.0% certainty. This assessment is strongly supported by the sample's highly similar structural patterns to multiple known instances of the Stealc malware family, indicating it is part of a sophisticated and active campaign.

Technical Analysis

The analysis reveals a highly structured Portable Executable (PE) file exhibiting strong genetic lineage to the Stealc malware family. The presence of numerous data directories, including IMPORT_TABLE, RESOURCE_TABLE, and TLS_TABLE, along with a HIGH_ENTROPY_VA DLL characteristic, are common architectural patterns observed in sophisticated malware designed for evasion and robust functionality. The use of a standard kernel32.dll import, combined with a GUI subsystem and a linker version of 14.43, suggests a deliberate effort to blend with legitimate Windows applications. The TLS section's presence, even with zero callbacks, is a notable structural indicator often leveraged by advanced threats for initialization or obfuscation.

The file's compilation timestamp of October 12, 2025, and its distribution across multiple nearly identical structural variants (geometric_similarity above 97%) point to a single, prolific development effort. These variants share identical section names like .rsrc, .idata, .tls, .themida, .boot, and .reloc, further solidifying their common origin. The consistent presence of a valid digital signature from "DigiCert Trusted G4 Code Signing RSA4096 SHA256 2021 CA1" across these samples, despite their malicious classification, is a critical observation indicating a determined adversary employing signature spoofing or compromise of legitimate signing infrastructure to bypass initial security checks and gain trust.

The observed structural patterns strongly suggest a malicious design intent focused on stealth and functionality. The specific combination of architectural choices and their near-identical replication across multiple samples implies a high degree of control and a common codebase or development framework being utilized by the threat actor. This level of structural convergence and evasionary technique points to a threat actor that invests significantly in maintaining operational security and sophisticated deployment capabilities.

Threat Intelligence Context

The detection assessment aligns with the known characteristics of the Stealc malware family. Stealc is a prevalent information stealer known for its ability to exfiltrate sensitive data such as browser credentials, cryptocurrency wallet information, system details, and files. Its typical attack vectors often involve phishing campaigns, exploit kits, or distribution through compromised websites. The observed structural similarities, particularly the compilation date and the presence of specific PE sections, are hallmarks of Stealc variants that have been active and evolving in the threat landscape.

The analyzed sample and its highly similar counterparts demonstrate a common development and distribution strategy. The consistent use of seemingly legitimate version information and valid digital signatures across these malicious files is a critical indicator of advanced adversary tradecraft. This suggests the attackers are either compromising legitimate software development pipelines or leveraging sophisticated signing services to disguise their malware as trusted applications. This multi-family attribution to Stealc, evidenced by the high geometric similarity scores and shared intelligence signatures, underscores the interconnectedness of these samples under a unified threat operation.

The integration of structural patterns with this intelligence reveals a deliberate campaign by threat actors to gain initial access and maintain persistence by masquerading as legitimate software. The near-identical structure across samples points to a single, well-resourced threat actor or group with a standardized development process for their Stealc-based tools. This level of consistency in construction, coupled with the use of valid signatures, suggests an adversary focused on high-volume distribution and a meticulous approach to evading detection.

Recommendations and Response Strategy

Given the definitive identification as Stealc malware, immediate actions should focus on containment and eradication. Prioritize the isolation of infected systems to prevent lateral movement and further data exfiltration. Conduct thorough network-wide scans for indicators of compromise (IOCs) related to Stealc, including the observed file hashes, network infrastructure, and any associated command-and-control (C2) communication patterns. Implement enhanced endpoint detection and response (EDR) rules to flag and block the specific structural characteristics observed, such as the presence of the .themida section in conjunction with the observed imports and data directories. Investigate the compromised signing certificates and associated entities to understand the extent of the breach and prevent further misuse. Remediation should involve the secure re-imaging of affected systems and a review of access controls and user privilege management to mitigate future exploitation.