id := 123456789
token := "ccgjhgjkhkjbhkb3d454bb6dd4b39ce43640e298a1374b5797eac0a3b05c9b57"
path := "C:\Users\blahblah\Desktop\face.jpg"

HTTP := ComObjCreate("WinHttp.WinHttpRequest.5.1")
HTTP.Open("GET", "https://api.vk.com/method/photos.getMessagesUploadServer?peer_id=" id "&access_token=" token "&v=5.103", true)
HTTP.Send()
HTTP.WaitForResponse()
RegexMatch(HTTP.responsetext, "upload_url"":""(.+?)""", match)
server := StrReplace(match1, "\/", "/")
objParam := {photo: [path]}
CreateFormData(PostData, hdr_ContentType, objParam)
HTTP.Open("POST", server, true)
HTTP.SetRequestHeader("Content-Type", hdr_ContentType)
HTTP.Send(PostData)
HTTP.WaitForResponse()
RegexMatch(HTTP.responsetext, "\{""server"":(.+?),""photo"":""(.+?)"",""hash"":""(.+?)""", match)
match2 := StrReplace(match2, "\""", """")
HTTP.Open("GET", "https://api.vk.com/method/photos.saveMessagesPhoto?server=" match1 "&photo=" match2 "&hash=" match3 "&access_token=" token "&v=5.103", true)
HTTP.Send()
HTTP.WaitForResponse()
msgbox % HTTP.ResponseText


; CreateFormData() by tmplinshi, AHK Topic: https://autohotkey.com/boards/viewtopic.php?t=7647
; Thanks to Coco: https://autohotkey.com/boards/viewtopic.php?p=41731#p41731
; Modified version by SKAN, 09/May/2016

CreateFormData(ByRef retData, ByRef retHeader, objParam) {
	New CreateFormData(retData, retHeader, objParam)
}

Class CreateFormData {

	__New(ByRef retData, ByRef retHeader, objParam) {

		Local CRLF := "`r`n", i, k, v, str, pvData
		; Create a random Boundary
		Local Boundary := this.RandomBoundary()
		Local BoundaryLine := "------------------------------" . Boundary

    this.Len := 0 ; GMEM_ZEROINIT|GMEM_FIXED = 0x40
    this.Ptr := DllCall( "GlobalAlloc", "UInt",0x40, "UInt",1, "Ptr"  )          ; allocate global memory

		; Loop input paramters
		For k, v in objParam
		{
			If IsObject(v) {
				For i, FileName in v
				{
					str := BoundaryLine . CRLF
					     . "Content-Disposition: form-data; name=""" . k . """; filename=""" . FileName . """" . CRLF
					     . "Content-Type: " . this.MimeType(FileName) . CRLF . CRLF
          this.StrPutUTF8( str )
          this.LoadFromFile( Filename )
          this.StrPutUTF8( CRLF )
				}
			} Else {
				str := BoundaryLine . CRLF
				     . "Content-Disposition: form-data; name=""" . k """" . CRLF . CRLF
				     . v . CRLF
        this.StrPutUTF8( str )
			}
		}

		this.StrPutUTF8( BoundaryLine . "--" . CRLF )

    ; Create a bytearray and copy data in to it.
    retData := ComObjArray( 0x11, this.Len ) ; Create SAFEARRAY = VT_ARRAY|VT_UI1
    pvData  := NumGet( ComObjValue( retData ) + 8 + A_PtrSize )
    DllCall( "RtlMoveMemory", "Ptr",pvData, "Ptr",this.Ptr, "Ptr",this.Len )

    this.Ptr := DllCall( "GlobalFree", "Ptr",this.Ptr, "Ptr" )                   ; free global memory 

    retHeader := "multipart/form-data; boundary=----------------------------" . Boundary
	}

  StrPutUTF8( str ) {
    Local ReqSz := StrPut( str, "utf-8" ) - 1
    this.Len += ReqSz                                  ; GMEM_ZEROINIT|GMEM_MOVEABLE = 0x42
    this.Ptr := DllCall( "GlobalReAlloc", "Ptr",this.Ptr, "UInt",this.len + 1, "UInt", 0x42 )   
    StrPut( str, this.Ptr + this.len - ReqSz, ReqSz, "utf-8" )
  }
  
  LoadFromFile( Filename ) {
    Local objFile := FileOpen( FileName, "r" )
    this.Len += objFile.Length                     ; GMEM_ZEROINIT|GMEM_MOVEABLE = 0x42 
    this.Ptr := DllCall( "GlobalReAlloc", "Ptr",this.Ptr, "UInt",this.len, "UInt", 0x42 )
    objFile.RawRead( this.Ptr + this.Len - objFile.length, objFile.length )
    objFile.Close()       
  }

	RandomBoundary() {
		str := "0|1|2|3|4|5|6|7|8|9|a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z"
		Sort, str, D| Random
		str := StrReplace(str, "|")
		Return SubStr(str, 1, 12)
	}

	MimeType(FileName) {
		n := FileOpen(FileName, "r").ReadUInt()
		Return (n        = 0x474E5089) ? "image/png"
		     : (n        = 0x38464947) ? "image/gif"
		     : (n&0xFFFF = 0x4D42    ) ? "image/bmp"
		     : (n&0xFFFF = 0xD8FF    ) ? "image/jpeg"
		     : (n&0xFFFF = 0x4949    ) ? "image/tiff"
		     : (n&0xFFFF = 0x4D4D    ) ? "image/tiff"
		     : "application/octet-stream"
	}

}

uploadFile(url, filePath)
{
	CreateFormData(postData, hdr_ContentType, { file: [ filePath ] })

	whr := ComObjCreate("WinHttp.WinHttpRequest.5.1")
	whr.Open("POST", url, false)
	whr.SetRequestHeader("Content-Type", hdr_ContentType)
	whr.Send(postData)

	if (whr.Status != 200)
		throw Exception(whr.responseText)

	return JSON.Load(whr.responseText)
}