GlobalSign expects to bring its certificate-issuing systems back online today and resume business Tuesday, it said over the weekend. The US certificate authority (CA) stopped issuing new SSL certificates last Tuesday in order to audit its security, after being named as a target by the hacker who claimed to have attacked Dutch CA DigiNotar.
The server hosting GlobalSign's website was breached, the company said Friday. The server was isolated from other infrastructure related to certificates, the company said.
On Sunday the company confirmed its earlier plan to bring system components back online Monday in a sequenced startup, but said customers were unlikely to be able to process orders until Tuesday morning.
It said that there was no further evidence of breach other than the isolated web server, but that it would be continuing to monitor all activity to all services closely as an additional precaution.
All forensics are being shared with the authorities and other CAs to assist with their own investigations into other potentially related attacks, GlobalSign said. It did not specify who the attacker was.
The company has employed security firm Fox-IT to investigate.
Fox-IT already has experience of this kind of investigation: It was hired by DigiNotar to discover how its servers were hacked. DigiNotar's servers had been used to issue hundreds of fake SSL certificates, including one for the domain google.com.
The attack on DigiNotar was discovered when an Iranian Gmail user noticed something amiss with the webmail service and the problem was traced to the fake certificate.
Close to 300,000 unique IP addresses from Iran requested access to google.com between 4 August and 29 August, while the rogue certificate was in use, according to Fox-IT's interim report for DigiNotar.
A hacker claimed last Monday in a message on Pastebin that he had broken into DigiNotar, and also had access to four other CAs including GlobalSign. The hacker is known as Ich Sun, or Comodohacker - a reference to the person's claims earlier this year to have broken into the servers of another certificate issuer, Comodo.