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

Static analysis result for SHA-256 64a459b00233e6ae…

MALICIOUS

Office (OLE) / .XLS

313.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 154cff6977e0b88138bbc0f1782bfc7f SHA-1: a44571e0a9b37264774b1c810b192ad3984da88e SHA-256: 64a459b00233e6ae1f8427c498a59deb86ed19655d52594e688d04f06f291795
282 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1105 Ingress Tool Transfer

The Excel file contains Excel 4.0 macros that are automatically executed via an Auto_Open entry. These macros construct a URL to download a file to 'C:\ProgramData\Freyrgb.dll' and then execute it using 'regsvr32 -s'. This indicates a downloader pattern aiming to execute a second-stage payload.

Heuristics 7

  • Reference to URLDownloadToFile API critical SC_STR_URLDOWNLOAD
    Reference to URLDownloadToFile API
  • 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
  • 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.
  • Suspicious extracted artifact medium EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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 http://vytyazhki.by/ds/291120.gif

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
49fcb491caaa166b3c1f74aaa4f2425ca343b5169399ee43c17188a500ea508e
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 983 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 shell/COM execution token(s).