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

Static analysis result for SHA-256 4689852a6e06ba83…

MALICIOUS

Office (OOXML) / .XLSM

102.2 KB Created: 2021-08-19 14:03:52 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2022-10-03
MD5: 10752bde286212b1e5ec01803a554c03 SHA-1: 862d54b78dd19d45a980f49201e6acca47857252 SHA-256: 4689852a6e06ba83be08fe943de1159aa8aaad7e1701b5fae5786ddd0930ba23
342 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

The Workbook_Open macro executes a command using cmd.exe and certutil.exe to download a file from the URL http://45.155.165.63/br1/loader/uploads/Doc_2050023_RFT.exe and save it as Bstsrrsxagmkhenpstz.exe.exe. This downloaded executable is then immediately executed, indicating a downloader or dropper functionality. The ClamAV detection further confirms its malicious nature.

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://45.155.165.63/br1/loader/uploads/Doc_2050023_RFT.exe

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
fc5a219fe63d692a7b05ae4743c0e7bb82bd2ae2df1db7fd37f4433601990d17		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1132 bytes
vbaProject_00.bin
34256c518cdaf3e7ae026e62a633b9b410eb964477617c788fbc20cbafbcbfb4		 vba-project OOXML VBA project: xl/vbaProject.bin 5632 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.