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

Static analysis result for SHA-256 098a9d7cbf79f402…

MALICIOUS

Office (OLE) / .XLS

525.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2021-05-26
MD5: ab88f6a2d99309d5f8b2e5626469ec76 SHA-1: e33d5b6a8fc0e41f5d0ea1a32eb6dea0939bfdab SHA-256: 098a9d7cbf79f402a0d8733909bec0729aea552c59a232bf2ca1172ac654f12c
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1203 Exploitation for Client Execution

This Excel 4.0 macro-enabled workbook uses an 'enable content' lure to trick the user into running its Auto_Open macro. The macro utilizes dangerous functions like CALL and EXEC, and attempts to download a payload from the URLs hxxps://rathnakumar.com/BuTxTGO63eD/solo.html and hxxps://maidzonemobile.com/Voy4zCN8y1/solo.html, likely to execute a second-stage payload using rundll32.exe or regsvr32.exe.

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://rathnakumar.com/BuTxTGO63eD/solo.html In document text (OLE body)
    • https://maidzonemobile.com/Voy4zCN8y1/solo.htmlIn document text (OLE body)