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

Static analysis result for SHA-256 4e032d4379c11f03…

MALICIOUS

Office (OLE) / .XLSX

78.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 66777cae6661259ed8a1353c75546ead SHA-1: 272e1039d8e68740839052c8bb430883cfd42a17 SHA-256: 4e032d4379c11f03cd0d137a7dbec749c0e926c8cc2e29e374d8c7ce8318e3f8
120 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled spreadsheet that impersonates DocuSign to trick the user into enabling macros. Upon enabling, the Auto_Open macro executes, which is designed to download and execute a second-stage payload from one of the embedded URLs. The macro uses the `rundll32` command with `DllRegisterServer` and `uRlMon` / `RLDownloadToFileA` functions, indicating a payload download and execution attempt.

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
8fc8eb4fe0d112b1cb5ac2ce2296b7e1ea4a0d10df9396b6e155f9c8f50eb7a8
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2293 bytes