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

Static analysis result for SHA-256 f05005feb32c7db2…

MALICIOUS

Office (OLE) / .XLS

31.0 KB Created: 2021-01-25 13:47:09 Authoring application: Microsoft Excel
MD5: c94ac457a09d91cabc77e706f08a6eba SHA-1: 6180b1684f41c5d551913df9a09cd9052c0371cf SHA-256: f05005feb32c7db2c7744ecde217c4cf8839643fc5d80bf0d32d1e77e2817d48
160 Risk Score

Malware Insights

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

The sample is an Excel 4.0 (XLM) macro-enabled spreadsheet. It contains an Auto_Open macro that uses dangerous functions, including the RUN function, indicating it is designed to execute arbitrary commands. The document body explicitly prompts the user to 'enable Editing and Content mode', a common lure to bypass macro security. No specific IOCs like URLs or hashes were extracted, but the presence of the Auto_Open macro and the lure strongly suggest a malicious downloader or dropper.

Heuristics 4

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
fc23829687783b55ad9f1864077820ba07301f18f24a6ea1db2961866d10d5bb
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3314 bytes