Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 a9bb46aa0641cd58…

MALICIOUS

Office (OLE) / .XLS

525.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2021-05-29
MD5: 44034cddd7ebad6fdda1ed674076b680 SHA-1: a4b775be4e6532698fc32a1f4777abcd2d21c942 SHA-256: a9bb46aa0641cd58ff63c177d97be2feb8059dae5a7e2b59bcbb4e9a798952df
142 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The presence of an Excel 4.0 macro sheet and a lure to enable macros strongly suggests a malicious intent. The embedded URLs likely point to payloads or further stages of the attack. The XLM macro sheet contains commands that appear to be related to downloading and executing files, indicated by 'downloadTFilLDo' and 'runDll'.

Heuristics 5

  • XLM Auto_Open workbook with payload URL or enable-content lure critical OLE_XLM_AUTOOPEN_PAYLOAD_LURE
    Workbook contains an Excel 4.0 macro sheet with Auto_Open / Auto_Close and also exposes a payload URL or enable-content lure in the OLE bytes. This combination is a high-confidence XLM downloader/social-engineering pattern even when formula recovery cannot decode the full macro chain.
  • Excel 4.0 (XLM) macro sheet uses dangerous capability functions high OLE_XLM_DANGEROUS_FN_STATIC
    Workbook contains an Excel 4.0 macro sheet whose formulas reference two or more dangerous capability functions (e.g. CALL into a Win32 API such as URLDownloadToFile, EXEC to launch a process, REGISTER an external DLL procedure, or FWRITE/FOPEN to drop a file) with an Auto_Open / Auto_Close auto-execution name. This is the canonical XLM downloader/dropper shape and is recovered directly from the BIFF records, so it fires even when the full macro chain cannot be deobfuscated.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://aravindanavada.com/AHt5r3T0VSlq/solo.html In document text (OLE body)
    • https://mrcrgroup.com/sOyQynNJYBY/solo.htmlIn document text (OLE body)