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

Static analysis result for SHA-256 f395dad731854b07…

MALICIOUS

Office (OLE) / .XLS

104.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: eb133cf122c308c5817ad4c46e2b26d6 SHA-1: 3788231a71ec854c197855a268c3a596607ae8dc SHA-256: f395dad731854b075365451f53b2f08a57511d4b907a230186da155b138fb17b
120 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro sheet with an Auto_Open macro, designed to impersonate a DocuSign request to lure the user into enabling macros. Upon enabling, it appears to execute a payload using rundll32.exe with DllRegisterServer, likely downloading and running a second-stage artifact from one of the provided URLs. The macro execution and lure techniques are clearly indicated by the heuristics.

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