Código PHP:
$url = "http://software-files-l.cnet.com/s/software/11/90/44/77/TeamViewer_Setup.exe?e=1307951605&h=c6292a895d5ac7cffff6961caac5645d&lop=link&ptype=1901&ontid=7240&siteId=4&edId=3&spi=e51a669e6b7a1b941ede7221052ce5dd&pid=11904477&psid=10398150&fileName=TeamViewer_Setup.exe";
$filename = basename($url);
echo $filename;