Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 fb0b72587b6dea32…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:27:20 Authoring application: Microsoft Excel
MD5: d08bacf0ca96e0246d4accd1c2a24f8c SHA-1: 87f851481c62cf2b65cd2cc4502bfad311010cee SHA-256: fb0b72587b6dea32aa08c7212090e9fb4e40b2938afa27bf16ce84a84b7dcfcd
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 defined name, which is a common technique for executing malicious code. The macro sheet contains a reference to a dangerous formula API, specifically 'RUN', suggesting it is designed to execute arbitrary commands. No specific IOCs like URLs or hashes were extracted, but the Auto_Open functionality itself is a significant indicator of malicious intent.

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
82bdb0dac51468c3e7febbb05f12bea8172fac3622e1dfc516af2292a05ea370
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6628 bytes