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

Static analysis result for SHA-256 819bffd779803a11…

MALICIOUS

Office (OOXML) / .XLSM

102.2 KB Created: 2021-08-19 14:03:52 UTC Authoring application: Microsoft Excel 15.0300
MD5: 1785128801ba1b1ae14879ae0eabab51 SHA-1: 2ad28d5b31f322939458bd60b52c109cf9f2ed84 SHA-256: 819bffd779803a115ab7f588d07723edaa97b855c3c7d95ad6bd209b59b9cd62
342 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

The Workbook_Open macro executes a command to download a batch file from http://18.156.129.63/entity/693900337383.bat using certutil and then executes the downloaded file. This indicates the sample acts as a downloader for a second-stage payload.

Heuristics 8

  • 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
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — 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://18.156.129.63/entity/693900337383.bat

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
7e9b5568704c28446b93f1d5029f2bfd8e695678899ec12704639955b8a28eb5
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1125 bytes
vbaProject_00.bin
6eeddfa5813b85f477b3f3d819213f8abe3e0f4370bdd207d991b70dc6300009
vba-project OOXML VBA project: xl/vbaProject.bin 5632 bytes
Detection
ClamAV: Xls.Dropper.EPPlus-9802867-2
Obfuscation or payload: unlikely