SquirrelWaffle — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 fe73fd3955380212…

MALICIOUS

Office (OLE) / .XLS

263.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 764987da4271d3dd9d7d9f8f78c897e5 SHA-1: 8df3093cfe00a49a1f86db5a4d6263a29ff30980 SHA-256: fe73fd3955380212aaecb045e92353f9684af4e89e4d1c183dd84a0b7271230b
242 Risk Score

Malware Insights

SquirrelWaffle · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious Link: Malicious File T1059.001 Command and Scripting Interpreter: PowerShell T1059.003 Command and Scripting Interpreter: Windows Command Shell

The file contains Excel 4.0 macros, specifically an Auto_Open defined name that utilizes dangerous functions like ShellExecute. This indicates the macro is designed to execute arbitrary commands. The presence of embedded URLs strongly suggests that these macros are intended to download and execute a second-stage payload. ClamAV also identified this file as SquirrelWaffle, a known downloader 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
3dbfa69f95b08bff069be35c6eadc78ae347e14ee3b85e46232e939c26a49ede		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 9185 bytes

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