A Lulz Security hacker group that bade farewell to the world last year appeared to make a comeback on Tuesday with a trove of data looted from a dating website for soldiers.

Hackers referring to themselves as "LulzSec Reborn" made a cache of information evidently stolen from MilitarySingles.com website available at online file sharing service Pastebin.

The file included a note saying "laughing at your security since 2011" and a message claiming to have mined personal information from nearly 171,000 accounts at the website.

In a message at an Anonymous News account at Twitter on Tuesday, the hackers promised to soon divulge "the full database of military singles" including private messages.

LulzSec, which was associated with loosely knit hacker collective Anonymous, announced in the middle of last year that it was dissolving the group after having caused 50 days of havoc as intended.

The farewell posted online came after suspected members of the group were arrested.

"The original LulzSec gang had its summer of hacktivism brought to a swift end," Graham Cluley said in a Sophos Internet security firm blog post on Tuesday.

"Of course, on the Internet, anyone can claim to be whatever they want and so it's not particularly surprising to see that it was a group calling itself LulzSec Reborn" claiming credit for a hack of MilitarySingles.com.

Cluley said that email address, real names and even home addresses of "romance-seeking members of the military" were in the trove of information posted on the Internet by the hackers.

"If you know anyone who has ever used the Military Singles website, it would be a good idea to tell them to change their password as a precaution - and to ensure that they are not using the same password anywhere else," Cluely advised.

ESingles Inc., which operates MilitarySingles.com, said it a public statement that it was investigating the hacking claim.