A fairly large amount of data from the company has been posted online, with the attackers claiming to have contacted company co-founder and joint owner Finn Lyskov who told them that it did not hold any important data.
According to the people behind this attack, the Excis site was breached on 30 May.
Lyskov's phone number was also published on the site, with the attackers saying, "feel free to ask him about 'Securing banks and military sites'!"
It has offices around the globe, including one in Queensland.
Among the services the company offers are compliance, business video, round-the-clock support, Wi-Fi expertise, data security consulting, looking after data centre servers and cabling, network operations centre functions, help desk, VoIP expertise, warehousing and logistics for IT and end-user support.
Excis staff have accreditations from Polycom. Cisco, Microsoft, IBM, HP, Hewlett Packard Enterprise, Juniper Networks, Wipro and Genpact, the company claims.
iTWire has contacted the company for comment.