Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f8d43957718aadee…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:41:14 Authoring application: Microsoft Excel
MD5: b39587001ca97cc48f2524a91230c3be SHA-1: fe93d3ead303d90dad2b9a76b4654bf92094b2e2 SHA-256: f8d43957718aadeea94bcc5b9fd35d1cee9a5cb00201d905fdc1f298cca2490a
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open entry, which is a critical indicator of malicious intent. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. This technique is commonly used for initial execution of malware or downloading secondary payloads.

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
f0b495fff0496e55158f044189b0d2746ff1816a810619ee962ca6cccff0831d		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6395 bytes

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