Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 f19f3c221cfd11f3…

MALICIOUS

Office (OOXML)

15.9 KB Created: 2021-06-08 07:44:17 UTC Authoring application: Microsoft Excel 16.0300
MD5: 70bb6b785c8e743124e7ab2e7351177f SHA-1: e0375e0b97bcf9f18c13ddbf4c5338ed24f8a03b SHA-256: f19f3c221cfd11f32d2548381f49ac5f39e9391079453f4418df78c2e59e166e
300 Risk Score

Malware Insights

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

The sample contains a Workbook_Open macro that executes VBA code. This code constructs a URL, downloads a file from it using Microsoft XMLHTTP, and saves it as 'C:\test\wp1\file.csv'. It then attempts to execute 'C:\Windows\System32\calc.exe' and copies 'cmd.exe' to 'c:\test\wp1\gg1.exe'. The VBA script's intent is to download and execute a second-stage payload, likely disguised as a CSV file, and then proceed with further execution.

Heuristics 7

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
78680daf3d08b42d68bc94c89a6a414d7342c099fd35870a3037ec05d0ea4e80		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2039 bytes
vbaProject_00.bin
8f3d8d176d17ba277d2352ff3278b441a459c306bfb31b6dac37308f873a463a		 vba-project OOXML VBA project: xl/vbaProject.bin 20480 bytes

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