The dangers are not due, necessarily, to vulnerabilities in the provider's service or network, but in the service's ubiquity and the lack of visibility that companies have into their workers' usage of the service, says Assaf Rappaport, co-founder and CEO of cloud-security startup Adallom. An employee, for example, could go home and sign into a company's cloud service from a family computer. If that computer is infected, then attackers have access to valuable business data.
This happened to one client, Rappaport says, and the result was the loss of its company's entire customer database.
"If I am the attacker, I am not going to breach the cloud service's back-end," he says. "I'm going to look at the weakest link, which is your users, because the easiest way to steal your data is to go through the front gate."
Cloud services are quickly being adopted by companies -- many times without official support -- and accessed by employees on a variety of personal devices that may not be secure. The average company has about 550 cloud services being used by employees, many of which are high-risk consumer services that do not have adequate security controls, according to data from Skyhigh Networks, a cloud-security provider. Software development, marketing, and productivity services are the least mature, according to a separate study by Netskope, a cloud-service risk management firm.
"I think cloud services expose a very big vulnerability," says Krishna Narayanaswamy, chief scientist at Netskope. "Companies are not aware of what their employees are using or how they are using it. It is a vector that is not covered by any existing technologies."
The major threat for companies using the cloud is the loss of user credentials. Attackers do not have to compromise the cloud provider to get access to a business' data because the providers do not typically check for what device or network a request originates, says Adallom's Rappaport.
"The most simple attacks that we saw a decade ago are the most effective in the SaaS world," he says. "If I have your credentials to Salesforce or Office365, then it is not relevant what endpoint and what network you are coming from."
[Scoring services seek to measure the security of almost every step of the business supply chain, from suppliers and transactions to applications and services. See Security Ratings Proliferate As Firms Seek Better Intel.]
Yet another threat is a compromised device. Because employees are increasingly bringing their personal devices into the workplace, or doing work from shared devices at home, companies are hard-pressed to secure the endpoints. Instead, they need to assess their use of cloud services to gain visibility into what is being used by employees.
Companies have to determine what cloud services employees are using, says John Howie, chief operating officer for the Cloud Security Alliance. Increasingly, third-party providers are offering reverse-proxy services to monitor employee usage of the cloud, but even offering incentives for employees to identify the cloud services they are using can improve visibility.
"If they don't know what data has been out of their control, it may require breach notification, and for that reason, some companies think ignorance is a better position to be in rather than knowing what is going on," Howie says. "And that is very scary."
Work with your employees who are using cloud services and get them to clean out their personal services of any corporate data, he says.
The vulnerability posed by cloud services needs to be managed, but the situation is not all that new, he adds. In the past, companies had to deal with business groups setting up their own servers and other hardware to offer their own collaboration services or file server, he says.
"Any business group could buy a server, stick it under someone's desk, and throw content on there," Howie says. "It the same thing today, except the business group is going to the cloud."
Yet companies also have to audit their users' usage of the cloud. Large companies can audit their own cloud usage and analyze the logs of users' activity, but a more common approach will likely be to use a third-party provider to log and analyze activity. A number of reverse proxy services, including Skyhigh Networks and Adallom's beta service, will allow companies to alert on anomalous activity.
"If an employee who normally downloads information on 10 clients a day is suddenly downloading 500 clients a day, then there is a problem," says Rajiv Gupta, co-founder and CEO of Skyhigh Networks.
While adding on auditing capabilities gives companies a more standard approach to assessing and analyzing their cloud usage, Gupta expects many providers of cloud business solutions to expose more security information to their customers. One reason: Scoring the trust level of the cloud service will give companies a metric on which to compete on their efforts, he says.
"What we expect that -- over time, as we show them the problems -- they will work with us to reduce the risk to their customers," Gupta says. "It's better for them and better for the industry."
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