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

Static analysis result for SHA-256 e0da86c488a274f9…

MALICIOUS

Office (OLE) / .XLS

80.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 550f926bdeb168cdd567fffebf11e24b SHA-1: 10ce1954929bd088c98d2c3fa8673bd17470de68 SHA-256: e0da86c488a274f97aff2edf379f2adb82b6b28681bcd9bd429ba8b29b40f442
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 entry, designed to execute code upon opening. It uses a DocuSign lure to prompt the user to enable macros. The macro sheet contains references to `rundll32`, `DllRegisterServer`, `URLMon`, and `URLDownloadToFileA`, indicating it attempts to download and execute a second-stage payload from one of the listed URLs. The presence of an Auto_Open macro and the user-enablement lure strongly suggest a downloader functionality.

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
22d3c31a465a6521900f39daf43eabaae00bc8bddcdeb66e5f53b58d567f7430
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2285 bytes