Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a2057ca36d8ba7ee…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:41:05 Authoring application: Microsoft Excel
MD5: caef107cfedd9ee277c0d9091c8cc3d9 SHA-1: b59c754f5b4cc12ea81e7786a528b640cc273528 SHA-256: a2057ca36d8ba7ee7863ebdc53a99d09a3903f4f92f0a524b0943d8b75cbef5a
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known technique for executing malicious code upon opening the workbook. The critical heuristics indicate the presence of dangerous formula APIs within the macro, suggesting it's designed to download and execute a secondary payload. No specific family could be identified, and no direct IOCs like URLs or hashes were extracted from the macro content itself.

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
cb88dc1842055e04e188957d5705a7b90af239d69a4ce91f6eb03036fbeb71d0
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6512 bytes