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

Static analysis result for SHA-256 56af77e2f4b36f94…

MALICIOUS

Office (OLE) / .XLSX

261.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: e56e32e50718813c2a9428de1d3ba674 SHA-1: 90cfd7975eadf45a34361e1a1def62ab1d81cad1 SHA-256: 56af77e2f4b36f94264cbb975bbea753fa5a4b2bec98a4fe8235d5ec28543fcb
120 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled spreadsheet that uses a lure to trick the user into enabling macros, impersonating a document signing service. The presence of an Auto_Open macro indicates that it will execute automatically upon opening. The macro sheet contains a reference to 'http://..\sdbybsd.fds', which is likely a URL for downloading a second-stage payload. The document body and sheet names also reinforce the DocuSign lure.

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
1cce783a487c585d0f0d553a6dcc92b7a1cc8611def516623538f51ccff16f05
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 4427 bytes