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

Static analysis result for SHA-256 8197cc1a97bf1973…

MALICIOUS

Office (OLE) / .XLS

31.0 KB Created: 2020-12-08 10:07:18 Authoring application: Microsoft Excel
MD5: 38c48b84e0724e0948ff34805f4be070 SHA-1: 39a32e03ffa32566aff95f070ef255519dbad874 SHA-256: 8197cc1a97bf19731af6fad62cc3bab8c0d68adecfa2870c3aa59a41b100bbbf
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro, which is a critical finding. This macro is designed to execute dangerous functions, including the RUN function, suggesting it's intended to download and execute a second-stage payload. The document body contains minimal text, and no specific URLs or executable content were directly extracted, but the presence of the Auto_Open macro and the 'enable macros' lure strongly indicate malicious intent.

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
e4351b318c5224a18cc04ad8b08a0977751812ceb89605864650453de23a6e8d
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3492 bytes