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

Static analysis result for SHA-256 166eb789fa6b7e92…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: ca4d2f3eff6dfebfd15824f22137fa16 SHA-1: 94ae60d88fc6115f162cb8dac61e50f3d0984651 SHA-256: 166eb789fa6b7e928eb9412fadf89d9b2d3c5e9769926f52f8744508e9c7fb6b
242 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros that are configured to automatically execute upon opening. These macros utilize the RUN and CALL functions to execute a downloaded payload from the URL `https://bgms.co.in/ds/261120.gif`. The `CALL` function appears to be constructing a command to download and execute a second-stage payload, evidenced by the concatenation of strings and the use of ShellExecute API references.

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://bgms.co.in/ds/261120.gif
    • https://bgms.co.in/ds/261120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
e213645668ce9f5d68f4226afb5b9b5e6c2ad49807658d9b833212b471c7c00d
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6675 bytes