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

Static analysis result for SHA-256 56f3554f76e6d63d…

MALICIOUS

Office (OLE) / .XLSX

58.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: c8778439ed104cb3f216179906808887 SHA-1: 34225e2167975defe119abd39f3f5c71668a925a SHA-256: 56f3554f76e6d63da78b4bf46e430567be688c179eb202b3b09ab5b46b4680a8
160 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 uses a DocuSign lure to entice the user to enable macros. Upon enabling, the Auto_Open macro executes a series of commands, including attempting to download a payload from http://www.psicheaurora.it/fanta/download.php using ndll32 and DllRegisterServer. This indicates a downloader or droppper 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.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
f4049687de69fbae7a0009d349264e905f03c629c5b7f7eb1990c6538d126bea
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2738 bytes