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

Static analysis result for SHA-256 729eb5e54fee645e…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: e6d9e5fd60e5ec954192c8bd1c971b90 SHA-1: 642352cb6f01528493f235aa9ac80d053327c65f SHA-256: 729eb5e54fee645ef080f98914bee8e7e893fe7fbb62aa77a939f97afcf50135
242 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros with an Auto_Open entry, which is a critical finding. These macros utilize dangerous functions like RUN and CALL to execute code. Specifically, the CALL function attempts to execute 'kernel32.dll' and 'crypt32.dll' with obfuscated arguments, and the RUN function points to a URL, 'https://fu5on.com/ds/231120.gif', which is likely used to download and execute a secondary 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://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

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