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

Static analysis result for SHA-256 e80c9a66c88172b3…

MALICIOUS

Office (OLE) / .XLS

48.5 KB Created: 2020-10-21 08:13:35 Authoring application: Microsoft Excel
MD5: a31830b208fcb237f9f7e5fc50bb41f3 SHA-1: ee54af4c285749c2a8b1de28ec03afde09c942b9 SHA-256: e80c9a66c88172b305f410b40ec4723a584346ca443e54d1726abab0d0596d84
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1059.003 Windows Command Shell

The file is an Excel 4.0 macro-enabled spreadsheet. Critical heuristics indicate the presence of an Auto_Open defined name, which is a common technique for automatic execution upon opening. The macro sheet contains dangerous formula APIs, specifically the 'RUN' function, suggesting it is designed to execute arbitrary commands. The extensive obfuscated data in the document body likely contains the payload or further instructions for execution.

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
113536a03044a444e20cb5467771c6efbc7df390a04cb2cbe0661a85a1250a29
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 13032 bytes