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

Static analysis result for SHA-256 2353abd006aede2a…

MALICIOUS

Office (OLE) / .XLS

42.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 1004b95833b9f3a098199876061b04d7 SHA-1: ad33657d132a5ff6bed053e4aea24fc4a34ec39d SHA-256: 2353abd006aede2a7eb61635bc1b2dc33c66d3ceec6b32eee65d5e540979d909
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The file is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro, which is a known technique for executing malicious code upon opening the document. The macro sheet contains references to dangerous formula APIs, specifically 'RUN', suggesting it is designed to execute arbitrary commands. The document body is heavily obfuscated and truncated, providing no clear user-facing lure, but the presence of the Auto_Open macro and the 'RUN' function strongly indicates a malicious intent to download and execute a second-stage payload.

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
be2dedbfe58bf7bb8d18897b389abd9915b04b3131f1bdcf9c4ad840fc2d1e06
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7860 bytes