Malicious Office (OOXML) / .XLSM — malware analysis report

Static analysis result for SHA-256 289dfc813d9f2a03…

MALICIOUS

Office (OOXML) / .XLSM

431.1 KB Created: 2021-08-19 14:03:52 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2022-04-14
MD5: fbe403c0e5a47dc56baed1b17932e217 SHA-1: c392b8d0ce62f0e2e28b0f167e434de48aaba784 SHA-256: 289dfc813d9f2a0375027fdfee69e447d46377d063c6fa72513d06a5b7898a7d
382 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1059.003 Windows Command Shell

The Workbook_Open macro executes a command using cmd.exe to download a batch file from the URL http://20.40.97.94/t7b/loader/uploads/SPE0451337.bat using certutil.exe. The downloaded file is then executed. This indicates a downloader or dropper functionality.

Heuristics 9

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • LOLBin reference in VBA critical OLE_VBA_LOLBIN
    LOLBin reference in VBA
  • ClamAV: Xls.Dropper.EPPlus-9802867-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.EPPlus-9802867-2
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
  • Suspicious extracted artifact high 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.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains vbaProject.bin — VBA macros present
  • 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://20.40.97.94/t7b/loader/uploads/SPE0451337.bat

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
3c5ce00192367279f9a64196115b9a26dc60aa84e4c221e9d09f541248f45b1f
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1131 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.
vbaProject_00.bin
4cb99f2fda6d1f92b419df17b17964351e0c8f4a039864598606354586121049
vba-project OOXML VBA project: xl/vbaProject.bin 5632 bytes
Detection
ClamAV: Xls.Dropper.EPPlus-9802867-2
Obfuscation or payload: unlikely