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

Static analysis result for SHA-256 507a6d57570a5774…

MALICIOUS

Office (OLE) / .XLS

274.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 96ac4b6f8184f21eadac4e4f719447de SHA-1: e67bb5d1240f2572dac3c4bf673cdfa13a1851c1 SHA-256: 507a6d57570a5774ce656a1b82535a4992e2320c6a760a5e957665263bf102cd
120 Risk Score

Malware Insights

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

This Excel 4.0 macro-enabled spreadsheet uses an Auto_Open macro to execute, which is a common technique for malware delivery. The document body contains a lure impersonating a document signing service, instructing the user to enable macros. The macro appears to download a DLL from 'https://parkisolutions.com/nerugin.dll' and execute it using 'rundll32.exe'. The presence of the Auto_Open defined name and the macro-enable lure strongly suggest a malicious intent to download and run a second-stage payload.

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
84db8022cd9373e19b3b88e0e3e8c161c0d41468768a7f50d479104c806845c5
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3274 bytes