SquirrelWaffle — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 4dec7e1492495740…

MALICIOUS

Office (OLE) / .XLS

263.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 8cd25260763711aec2372ed827ea6e84 SHA-1: 4d115388323a5aeb69082b8da063d83322b855cf SHA-256: 4dec7e1492495740ed14d697dd112b6afdd80b4a38fe2adbca391299568cbf14
242 Risk Score

Malware Insights

SquirrelWaffle · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File T1059.001 PowerShell T1059.003 Windows Command Shell T1059.004 JScript/VBScript

The file contains Excel 4.0 macros, specifically an Auto_Open defined name that utilizes dangerous functions like ShellExecute. This indicates an attempt to download and execute a second-stage payload from one of the embedded URLs. The ClamAV detection name 'Xls.Downloader.SquirrelWaffle20921-9895790-0' strongly suggests the SquirrelWaffle family.

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: Xls.Downloader.SquirrelWaffle20921-9895790-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.SquirrelWaffle20921-9895790-0
  • 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://cortinastelasytrazos.com/Yro6Atvj/sec.html
    • https://orquideavallenata.com/4jmDb0s9sg/sec.html
    • https://fundacionverdaderosheroes.com/gY0Op5Jkht/sec.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
125eeb65449215b38b4c93bcf67effc9a2990373b692ed6d0729f78b6e651f74
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 9167 bytes