Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 84fe31701700aa7c…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:24:35 Authoring application: Microsoft Excel
MD5: 022f88ebae35556cfed9068c5381b844 SHA-1: d24d80185f4d1493e5c2375b1f628c2c45e1ce6b SHA-256: 84fe31701700aa7c6174365cc2f7a0f4884cfb76db4251d1e5cbd48c64fb65d3
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 macro, which is a critical finding. This type of macro is known to be used for executing arbitrary code, often to download and run additional malicious content. The presence of dangerous formula APIs further supports this malicious intent. No specific URLs or hashes were extracted, but the technique itself is highly indicative of a downloader or initial execution stage.

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
d5c263490945703cdcaf30b323d488682612acefe512ccbae72306000365dd8d
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6676 bytes