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

Static analysis result for SHA-256 651c2182c3ecf99a…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 05d5e70604a6db1d690e85bf8eff894f SHA-1: 134540745a878821be240f1a4c9c7d132c1102c1 SHA-256: 651c2182c3ecf99a63e1546035655340f121ef12e0852bb3c2299e6c65ae5d43
242 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file contains Excel 4.0 macros, including an Auto_Open entry, which is a critical finding. The macros attempt to execute a command using CALL("Ke"& DocuSig!JE349&"32","Cr"& DocuSig!JG377&"yA","JCJ", DocuSig!IV347& DocuSig!IV362,0), which likely downloads and executes a second-stage payload from the embedded URL https://fu5on.com/ds/231120.gif. This indicates a downloader attack pattern.

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 https://fu5on.com/ds/231120.gif
    • https://fu5on.com/ds/231120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
fc23abdcb2657b335d0fb386451be5be98110592c06d0600d83d33c16e5bacb2
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6295 bytes