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

Static analysis result for SHA-256 b7eeecfbdece6906…

MALICIOUS

Office (OLE) / .XLS

41.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 61cada92a25ac4a5afafca0c24387f5e SHA-1: f07fc0ddabd881be3eafb2b165e7248f0cf42c1f SHA-256: b7eeecfbdece6906019360d76eb62d435c73cb7e553014607398b04dd8779d6e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1059.001 Command and Scripting Interpreter: PowerShell T1059.003 Command and Scripting Interpreter: Windows Command Shell

The sample is an Excel 4.0 macro-enabled spreadsheet. Critical heuristics indicate the presence of an Auto_Open macro and the use of dangerous formula APIs, specifically the RUN function. This suggests the macro is designed to execute arbitrary commands upon opening. No specific URLs or hashes were extracted, but the technique strongly implies 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
fc01d5e60727d2751e47ab72734566f1b64f5c775a229179e758511ba4e9ace7
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8031 bytes