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

Static analysis result for SHA-256 6e1b6ac6923418e9…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 805d1aac263d79555448968b734b7593 SHA-1: b6ef0ecc67491f94548e90d9ea5e081a17f4840b SHA-256: 6e1b6ac6923418e99a02e64223a097127936341c167966e97aa61f6204845b89
242 Risk Score

Malware Insights

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

The sample contains Excel 4.0 macros with an Auto_Open entry, indicating automatic execution upon opening. The macros utilize dangerous functions like RUN and CALL, and construct strings that appear to be API calls and URLs. Specifically, the macro attempts to execute code by calling ShellExecute indirectly and downloads a payload from 'https://oyefauji.com/ds/261120.gif'. This suggests a downloader functionality.

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://oyefauji.com/ds/261120.gif
    • https://oyefauji.com/ds/261120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
58a4f5727165121d868a3a8deb557c7e948c3b637eb6aacf726ea069bd257a4e
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6677 bytes