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

Static analysis result for SHA-256 96eaa313abb56196…

MALICIOUS

Office (OLE) / .XLS

67.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-05-23
MD5: 3cfaa4009799dc19f12161241bbf7b03 SHA-1: f36b5b095c84f4cf7e01eaf23de008a3362843a8 SHA-256: 96eaa313abb56196eea9e8c4c20f78166b79894652e1cff740729d17aace22f0
140 Risk Score

Malware Insights

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

The sample contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical heuristic firing. The macros are designed to execute dangerous functions, including the RUN function, indicating an intent to download and execute a second-stage payload. The embedded URLs are the most likely sources for this payload. The presence of an Auto_Open macro sheet strongly suggests an automated execution path upon opening the document.

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
67f6b164c4d6ea1ea8efe2ccdff056dde7fd1072da2bb20afe3b275864086c71
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7678 bytes