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

Static analysis result for SHA-256 c63a58db4d75e8cd…

MALICIOUS

Office (OLE) / .XLS

117.5 KB Created: 2007-11-11 00:07:00 Authoring application: Microsoft Excel
MD5: 431c64cdb8790928ca0438ecf09ab299 SHA-1: 948d34a87f542b8b78d6cc130d5b015dfeb3c8c3 SHA-256: c63a58db4d75e8cd3f9b0a9769d541a86ad65b32b73d5ab9e801ee53572b3c98
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 (XLM) macro-enabled spreadsheet. It contains an Auto_Open macro that uses dangerous functions, specifically the RUN function, indicating an attempt to execute external code. The document body claims the file is encrypted and prompts the user to enable editing and content, a common social engineering tactic to bypass security warnings and facilitate payload execution. The presence of the Auto_Open macro and the deceptive document body strongly suggests a downloader or initial access mechanism.

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
8fb49db9d186fef064c3692037103d04b898412057851f4e3cb7e7d3d3751de4
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 60052 bytes