Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 50db4bec58848fc5…

MALICIOUS

Office (OOXML)

777.8 KB Created: 2021-06-22 12:30:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: 196977d3c5e6d635fdd60ac4d9f5e127 SHA-1: ad248cdd39e1024362c9c764b7a43b93f00c9dca SHA-256: 50db4bec58848fc5c5bee3a098b439c4bb5636873ff44b882b0c09c6c898fed4
250 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer T1566.001 Spearphishing Attachment

The sample is an OOXML document containing a VBA macro with an AutoOpen subroutine. This macro is designed to execute a second-stage payload by downloading it from the hardcoded URL "http://188.166.41.131/momo.php". The presence of the AutoOpen macro and the download functionality strongly suggests a malicious dropper.

Heuristics 9

  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • 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.
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
  • 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://188.166.41.131/momo.php
    • http://188.166.41.131/momo.php�
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas
    • http://schemas.microsoft.com/office/drawing/2014/chartex
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartex
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartex
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.microsoft.com/office/drawing/2016/ink
    • http://schemas.microsoft.com/office/drawing/2017/model3d
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/officeDocument/2006/math
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawing
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing
    • http://schemas.openxmlformats.org/wordprocessingml/2006/main
    • http://schemas.microsoft.com/office/word/2010/wordml
    • http://schemas.microsoft.com/office/word/2012/wordml
    • http://schemas.microsoft.com/office/word/2018/wordml/cex
    • http://schemas.microsoft.com/office/word/2016/wordml/cid
    • http://schemas.microsoft.com/office/word/2018/wordml
    • http://schemas.microsoft.com/office/word/2020/wordml/sdtdatahash
    • http://schemas.microsoft.com/office/word/2015/wordml/symex
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroup
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInk
    • http://schemas.microsoft.com/office/word/2006/wordml
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShape

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
0fa605beb8a149eab247d5f2dcd1c795299b51fa972e77216e8ed06a703c7aa8
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2348 bytes
vbaProject_00.bin
bd03994ed0a5d14dba88ab371033efed307d3fdb28d476d369fb49cec2cd37b6
vba-project OOXML VBA project: word/vbaProject.bin 13312 bytes