SINGAPORE — StarHub has yet to determine the root cause of the disruptions faced by its customers on Saturday (Oct 22) and again on Monday, but said there were similarities between the two incidents.  

The Cyber Security Agency (CSA) and the Infocomm Media Development Authority (IMDA) also said the possibility of a cyberattack cannot be ruled out. In a joint statement, the CSA and IMDA said: "We have been paying close attention to developments as it happened on the heel of Friday’s attack against the US-based Domain Name System service provider, Dyn. We cannot rule out the possibility that this was a DDOS attack. What is important now is for StarHub to determine the root cause of the problem and prevent a recurrence." 

A  distributed denial-of-service (DDoS) attack typically occurs when multiple systems flood the bandwidth of a targeted system.

StarHub said in a separate statement on Tuesday that the disruption on Monday night was due to a spike in data traffic to their Domain Name Servers (DNS), and as such affected "some of our home broadband customers". It added that the service was fully restored at about 11.25pm the same day. 

"There was no impact on mobile, enterprise and home voice services, and the security of our customers’ information was not compromised," StarHub said.

The IMDA is working with StarHub to investigate the matter, and strengthen its infrastructure and processes. 

Other telcos have been advised to step up their defences in case there are similar disruptions to their systems. The CSA is also “studying and addressing the risks of DDoS attacks on our communications systems, as well as the measures to mitigate the impact of such attacks if they happen. CSA will also reach out to educate the public and businesses on the need to properly secure their systems”, the statement added.

Frustrated StarHub fibre broadband users were unable to connect to the Internet on Monday night, the second such disruption in three days. 

From about 10pm on Monday, users had posted on StarHub’s Facebook page complaining of the service disruption. According to users, areas affected included Toa Payoh, Ghim Moh and Tanah Merah.

StarHub said on Facebook at 10.40pm that that it was aware that “some broadband customers” have been facing difficulties. “We are looking into this right now, and will post updates here as soon as we can,” the telco added. StarHub later updated that a network equipment issue had affected residential broadband service since about 10pm on Monday. The issue was rectified at 11.20pm, and the telco was investigating the root cause of the incident.

Facebook user Stephen Lam wrote: “Thanks for acknowledg(ing) that you are aware of the issue. Now please get it fix at the soonest, while I understand technical issue could be unpredictable but it is very annoying to experience disruption twice in 72 hours.”

According to figures on downdetector.sg, which offers a realtime overview of status information and outages for digital services, the number of outage reports peaked at more than 3,400 at close to 11pm on Monday.

On Saturday, StarHub broadband users were plagued by similar issues. The outage was rectified the next day at 2am. StarHub said on Facebook that the outage was due to “a network equipment issue”.