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

Static analysis result for SHA-256 0045e4acf0984e39…

MALICIOUS

Office (OOXML) / .XLSM

389.1 KB Created: 2020-01-28 19:47:00 UTC Authoring application: Microsoft Excel 15.0300
MD5: eabbe2b02e87fb058064b35a49885889 SHA-1: 5dc0bc9994ee61bf6ce649aad32151de2cd0af9d SHA-256: 0045e4acf0984e3982a7b0c31f8c36ce86528657bf1a41c2b5cefc71b75e9c01
370 Risk Score

Malware Insights

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

The sample is an XLSM file containing a Workbook_Open macro that executes a command using cmd.exe. This command uses certutil.exe to download and execute a second-stage payload from the URL http://18.159.59.253/cut/Aiacnr.exe. The document body contains instructions that attempt to trick the user into enabling macros, which is a common lure technique.

Heuristics 10

  • 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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • External hyperlinks (6) low OOXML_EXTERNAL_HYPERLINKS
    Document contains 6 external hyperlinks — clickable URLs are stored as external relationships. First target: https://go.microsoft.com/fwlink/?linkid=844736
  • 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://18.159.59.253/cut/Aiacnr.exe
    • https://go.microsoft.com/fwlink/?linkid=844736
    • http://go.microsoft.com/fwlink/?LinkId=844969
    • https://go.microsoft.com/fwlink/?linkid=844749
    • https://go.microsoft.com/fwlink/?linkid=844741
    • https://go.microsoft.com/fwlink/?linkid=844732
    • https://go.microsoft.com/fwlink/?linkid=844725
    • https://go.microsoft.com/fwlink/?linkid=844742
    • https://go.microsoft.com/fwlink/?linkid=844734
    • https://go.microsoft.com/fwlink/?linkid=844751
    • https://go.microsoft.com/fwlink/?linkid=844745
    • https://go.microsoft.com/fwlink/?linkid=844743
    • https://go.microsoft.com/fwlink/?linkid=844728
    • https://go.microsoft.com/fwlink/?linkid=844746
    • https://go.microsoft.com/fwlink/?linkid=844747
    • https://go.microsoft.com/fwlink/?linkid=844726
    • https://go.microsoft.com/fwlink/?linkid=844738
    • https://go.microsoft.com/fwlink/?linkid=844735
    • https://go.microsoft.com/fwlink/?linkid=844750
    • http://go.microsoft.com/fwlink/?LinkId=846285

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
97a0cfa83dbcb359ec70de7cd091430c11e1e21caa0a9d1ea8cfa09e2b9aa18f		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 4441 bytes
vbaProject_00.bin
a845121debc38efc00716cc893e2bb23f6f17cd82402e05538db67c1b1fcd11f		 vba-project OOXML VBA project: xl/vbaProject.bin 9728 bytes
Detection
ClamAV: Xls.Dropper.EPPlus-9802867-2
Obfuscation or payload: unlikely

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