Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 95488acb67a049af…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:39:21 Authoring application: Microsoft Excel
MD5: dd092ea90bb139010f39ad57556da153 SHA-1: d1c4a9ea75d58de8c22863c942d31d5acdfc6966 SHA-256: 95488acb67a049aff4dc38a0d8f7bb9faf6dd5a51e8a0df72779ff604b1db10d
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, specifically using dangerous formula APIs like RUN. This suggests the macro is designed to execute arbitrary code upon opening the document. While no specific URLs or payloads were extracted, the technique strongly implies the macro's purpose is to download and execute a second-stage payload.

Heuristics 3

  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
59106853f78c59bec3433d6054b32fd6a4a28f1cbeac34ff15a7a979c51c0c13
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6519 bytes