It only "unobfuscates" things that are numeric, such as the example shown, which is a hexadecimal number, or decimal numbers such as '218020952'. This might appeaear in a URL as: http://218020952/dirty-pictures.html However, a persual of more recent spam shows few using this form any more. More typical examples also include HTML escaping, eg:

http://%77%77%77%2E%66%70%63%6D%61%67%61%7A%69%6E%65%2E%6E%65%74/
[download]

for this form, use

perl -MURI::Escape -e ' print uri_unescape("http://%77%77%77%2E%66%70%
+63%6D%61%67%61%7A%69%6E%65%2E%6E%65%74/") . "\n"'
[download]

where the preceding was all on one line.

Bob Niederman, http://bob-n.com