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

Static analysis result for SHA-256 1060b6b6d4bcf94b…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 8ef590c572f91d7250558a9b7a23d191 SHA-1: e4a970e0279775b227ecac74e2ce6f9ac2441235 SHA-256: 1060b6b6d4bcf94b5942e81759325f06d9b5c57b17e5d0ea3ff306f1bc9f9525
242 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

This Excel 4.0 macro-enabled workbook contains an Auto_Open macro that executes a formula. The formula calls a 'CALL' function with concatenated strings that appear to resolve to 'rundll32.exe' and 'CreateA'. It also contains a URL pointing to 'http://ski-travel.pl/ds/231120.gif', which is likely used to download and execute a second-stage payload. The presence of the Auto_Open macro and the ShellExecute API reference strongly indicate malicious intent.

Heuristics 6

  • 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.
  • ClamAV: Doc.Downloader.Docusign0521-9864805-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Docusign0521-9864805-0
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://ski-travel.pl/ds/231120.gif
    • http://ski-travel.pl/ds/231120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
d0d7060848f9e43377c289847dba3120f97cf87e725bc4bc328c35415fe210f7
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6298 bytes