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

Static analysis result for SHA-256 5748df0b5c29bedb…

MALICIOUS

Office (OLE) / .XLSX

143.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2022-05-31
MD5: 9ae08efb58e4476f732ce254eac72c86 SHA-1: 58322b40d2ccea4330fd23a1fd41ea4b29110862 SHA-256: 5748df0b5c29bedb9a7f24fce01bc28fd7b3d2cb390501df9ee23062997addb2
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1204.002 Malicious File

The sample contains Excel 4.0 macros with an Auto_Open entry, indicating automatic execution upon opening. The document body and heuristics suggest a lure impersonating DocuSign to trick the user into enabling macros. The extracted URLs are likely part of the payload delivery chain. The XLM macros are too truncated to determine the exact execution flow, but the presence of Auto_Open and the lure strongly suggests a downloader or initial access mechanism.

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
c06303a4d2d9f3242c9a0e11a903b4059f80ff43a79c026b8de7cea5292556c9
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2730 bytes