Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d837adf56981ada2…

MALICIOUS

Office (OLE)

171.0 KB Created: 2020-05-14 09:40:00 Authoring application: Microsoft Excel
MD5: fb5f0c0748d07ae04b967ebd36baa5d5 SHA-1: 1f60dd2785ffa3e36127e40d0490e8b95715b6ce SHA-256: d837adf56981ada28bbbd0116c7acd282f19a74135b32b0e48505425db97fda4
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook. Heuristics indicate the presence of an Auto_Open macro, which is a common technique for executing malicious code automatically when the workbook is opened. The macro uses dangerous functions, including 'RUN', suggesting it attempts to execute arbitrary commands or payloads. The specific function call 'RUN=36' is a critical 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
c358e641849b7ae1956721d7040f538a7b368c1d1733ca2a7e8fb5e86a41b3d7
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 129363 bytes