underscore parameter in QUERY STRING - Possible attack?

[ClubKnowledge]

I am seeing 5 or 6 of these kind of queries per day recently
/?_=1281728282196 .. the number seems to increment each time.

Are they trying to set perls $_ variable?

Anyone know what they might be trying to do?

Thanks
Walt

[lammert]

Hi Walt, welcome to the webmaster community here!

1281728282196 is a time specifier in milliseconds. Many Linux based computers and programs keep the time in terms of the number of seconds since 1-1-1970 0:00:00. Your value 1281728282.196 translates to the following date Fri Aug 13 21:38:02.196 2010.

I don't know why you see these parameters now though. I use them on one of my sites as dummy parameters where pages change rapidly and a periodical refresh is therefore mandatory to see the newest content. Adding a dummy parameter with a continuously changing parameter prevents the cached content of a page to show up again at the next refresh. Maybe people therefore add this parameter to prevent cashing in their browser or intermediate proxies.

[ClubKnowledge]

Thanks for the info .. I have used the same idea on occasion so images will refresh in Capta code