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

Static analysis result for SHA-256 7846675876858eb7…

MALICIOUS

Office (OLE) / .XLSX

104.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 7473c6f533cb70a6cd62dbfb8e475629 SHA-1: 76e3db993d597226a88da917ac4a705b9e6ac98e SHA-256: 7846675876858eb7d9c6df918cf7e603ee196c57bff7b5ad9c7289bf20164d13
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic

The sample contains Excel 4.0 macros with an Auto_Open entry, indicating it will execute automatically when the workbook is opened. It also contains a lure to enable macros, impersonating a document signing service. The macros appear to be designed to download and execute a payload using rundll32.dll, likely from one of the embedded URLs.

Heuristics 4

  • 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.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Document signing service impersonation lure medium SE_DOCUSIGN_LURE
    Document impersonates DocuSign, Adobe Sign, or a similar signing service in a signing-request context

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
f6f94d67da6884829caad9c6254d35920c4ca40818ef183c6a43675671038d32
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3048 bytes