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

Static analysis result for SHA-256 66b3a5145de030d2…

MALICIOUS

Office (OLE) / .XLS

330.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: a59e38a68bb93bf744c10792711eb409 SHA-1: 04c9e1bf32783d094be1d5ddcc13bebd9e005df9 SHA-256: 66b3a5145de030d24f202fa4bdd39b063f37736600a5416169f9652946d1af93
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 with an Auto_Open entry, which is a critical finding. These macros utilize the RUN function and a CALL to kernel32.dll's CreateA function, indicating an attempt to execute code. The macro also references the URL https://rlink011.pw/ds/231120.gif, suggesting it's designed to download and execute a second-stage payload. The presence of ShellExecute API references further supports this 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 https://rlink011.pw/ds/231120.gif

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
c461ade38d400d4a423d855884def8ceb5c41198f9e35b0fb284854a9f7c58df		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6059 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.