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

Static analysis result for SHA-256 9dbb10bc210809b8…

MALICIOUS

Office (OLE) / .XLSX

113.0 KB Created: 2013-06-01 03:53:00 Authoring application: Microsoft Excel
MD5: 39b46c56d2e1ef19708ea59e50d947f9 SHA-1: 9495e6bcdd560a7fdabe4feee0c180972b94260f SHA-256: 9dbb10bc210809b85f7df59706d52353fb5eafa4fa098de6dfaa8a5eaae114c1
140 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled workbook. It contains an Auto_Open macro, which is a known technique for executing malicious code upon opening the document. The document body text is a lure, instructing the user to 'Enable Editing' and 'Enable Content' to view or edit the document, which is a common social engineering tactic. The presence of the Auto_Open macro and the deceptive document body strongly suggest the intent is to execute arbitrary code.

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
5f01e06a308094392c9348c2c5e3fa7dca5afcbe87935062362366f29da8dd49
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 59866 bytes