SquirrelWaffle — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 00189ae30ede41db…

MALICIOUS

Office (OLE) / .XLS

235.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 1be7f7b227794a5163676d8f017d516c SHA-1: 5fc6670e292f1d1b18d1df8868787a99c38fd1a5 SHA-256: 00189ae30ede41db97df3adb41e962c6d08534ca421cf30147b23d1cd46f2228
262 Risk Score

Malware Insights

SquirrelWaffle · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The file contains Excel 4.0 macros, specifically an Auto_Open function that is designed to execute automatically. The macros reconstruct and call URLs, indicating a downloader functionality. The ClamAV detection name 'Xls.Downloader.SquirrelWaffle1021-9903731-0' strongly suggests the SquirrelWaffle family and a downloader attack pattern.

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.
  • URL reconstructed from XLM cell array (3 URLs) critical OLE_XLM_CELL_ARRAY_URL
    Excel 4.0 macro sheet stages its payload URL across the BIFF8 Shared String Table (one quoted-char SST entry concatenated with & at runtime) or across individual numeric cells (one ASCII charcode per cell). The reconstructed URL is invisible to literal-bytes URL extraction because it is never contiguous in the workbook stream. URLs were recovered by walking the BIFF8 record stream and decoding SST entries plus LABELSST/RK/NUMBER cells.
  • ClamAV: Xls.Downloader.SquirrelWaffle1021-9903731-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.SquirrelWaffle1021-9903731-0
  • 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.
  • 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://pdmgtc.org/zndmZgKgKNJO/nature.html
    • https://coronavirusexplanation.com/K6LHv4xQHwL8/natur.html
    • https://silverliningohio.com/dWuiynkrpd/natu.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
5e8ff13675c4fd39e2f06a809a3bf386a38dc86cf57484bef0b10a5599c21569		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 10967 bytes

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