Lulz Security claimed responsibility for stealing the personal details of more than 1 million users at Sony Pictures Entertainment on Friday.
Japanese games company Nintendo confirmed an intrusion at one of its affiliates in the US, but says no consumer data or company information was lost.
"The protection of our customer information is our utmost priority, and we constantly monitor our security," said Nintendo spokesman Tomokazu Nakaura in a statement.
Lulz Security (LulzSec) published a server configuration file, purportedly from a Nintendo secure server on the internet, but said via Twitter that it was not targeting Nintendo, according to the Guardian.
LulzSec said on Twitter that it hoped Nintendo plugged the gap, and later confirmed that the security hole it had identified had been fixed.
"We love Nintendo and Sega, if anything we'd hack *for* them. If you're listening Nintendo/Sega, you, you uh... you want Sony hacked more?" LulzSec tweeted.
Last week's attack on Sony Pictures Entertainment, in which personal details were stolen, is the latest breach in a series of attacks on high-profile companies including defence firm Lockheed Martin, US public news service PBS, Google's Gmail division, and RSA, the security division of EMC.
Against this background, the US is set to publish plans that will categorise cyber attacks as acts of war, according to the BBC.
In future, a US president could consider economic sanctions, cyber retaliation or a military strike if key US computer systems were attacked, US officials have said recently.
A report on the issue is expected from the Pentagon is expected within weeks.
This story was first published by Computer Weekly