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

Static analysis result for SHA-256 b6749817ce9452e1…

MALICIOUS

Office (OLE) / .XLS

82.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 0ea37fca5f366b0fb584cf66e7d64e19 SHA-1: 40fae8524d74a5eae16ece4adb80c8eb09a9cc8e SHA-256: b6749817ce9452e12bd664d7165b1986875359cb96b2579380e3e83cc441e148
120 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.005 Visual Basic T1218.011 Rundll32

The sample is an Excel 4.0 macro-enabled spreadsheet that impersonates DocuSign to lure users into enabling macros. The Auto_Open macro executes rundll32 with DllRegisterServer, likely to download and execute a second-stage payload from one of the embedded URLs. The presence of the Auto_Open macro and the explicit lure to enable content strongly indicate a malicious intent.

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
289f1ecba7cfa64d7702ff01d87584cb998b5d0e6feb4e401d737cdda073dd07
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2292 bytes