- Cloud malware injection attacks
Malware injection attacks are done to take control of a user’s information in the cloud. For this purpose, hackers add an infected service implementation module to a SaaS or PaaS solution or a virtual machine instance to an IaaS solution. If the cloud system is successfully deceived, it will redirect the cloud user’s requests to the hacker’s module or instance, initiating the execution of malicious code. Then the attacker can begin their malicious activity such as manipulating or stealing data or eavesdropping.
- Abuse of cloud services
Hackers can use cheap cloud services to arrange DoS and brute force attacks on target users, companies, and even other cloud providers. For instance, security experts Bryan and Anderson arranged a DoS attack by exploiting capacities of Amazon’s EC2 cloud infrastructure in 2010. As a result, they managed to make their client unavailable on the internet by spending only $6 to rent virtual services.
An example of a brute force attack was demonstrated by Thomas Roth at the 2011 Black Hat Technical Security Conference. By renting servers from cloud providers, hackers can use powerful cloud capacities to send thousands of possible passwords to a target user’s account.
- Denial of service attacks
DoS attacks are designed to overload a system and make services unavailable to its users. These attacks are especially dangerous for cloud computing systems, as many users may suffer as the result of flooding even a single cloud server. In case of high workload, cloud systems begin to provide more computational power by involving more virtual machines and service instances. While trying to prevent a cyber attack, the cloud system actually makes it more devastating. Finally, the cloud system slows down and legitimate users lose any availability to access their cloud services. In the cloud environment, DDoS attacks may be even more dangerous if hackers use more zombie machines to attack a large number of systems.
- Side channel attacks
A side channel attack is arranged by hackers when they place a malicious virtual machine on the same host as the target virtual machine. During a side channel attack, hackers target system implementations of cryptographic algorithms. However, this type of threat can be avoided with a secure system design.
- Wrapping attacks
A wrapping attack is an example of a man-in-the-middle attack in the cloud environment. Cloud computing is vulnerable to wrapping attacks because cloud users typically connect to services via a web browser. An XML signature is used to protect users’ credentials from unauthorized access, but this signature doesn’t secure the positions in the document. Thus, XML signature element wrapping allows attackers to manipulate an XML document.
For example, a vulnerability was found in the SOAP interface of Amazon Elastic Cloud Computing (EC2) in 2009. This weakness allowed attackers to modify an eavesdropped message as a result of a successful signature wrapping attack.
- Man-in-the-cloud attacks
During this type of attack, hackers intercept and reconfigure cloud services by exploiting vulnerabilities in the synchronization token system so that during the next synchronization with the cloud, the synchronization token will be replaced with a new one that provides access to the attackers. Users may never know that their accounts have been hacked, as an attacker can put back the original synchronization tokens at any time. Moreover, there’s a risk that compromised accounts will never be recovered.
- Insider attacks
An insider attack is initiated by a legitimate user who is purposefully violating the security policy. In a cloud environment, an attacker can be a cloud provider administrator or an employee of a client company with extensive privileges. To prevent malicious activity of this type, cloud developers should design secure architectures with different levels of access to cloud services.
- Account or service hijacking
Account or service hijacking is achieved after gaining access to a user’s credentials. There are various techniques for achieving this, from fishing to spyware to cookie poisoning. Once a cloud account has been hacked, attackers can obtain a user’s personal information or corporate data and compromise cloud computing services. For instance, an employee of Salesforce, a SaaS vendor, became the victim of a phishing scam which led to the exposure of all of the company’s client accounts in 2007.
- Advanced persistent threats (APTs)
APTs are attacks that let hackers continuously steal sensitive data stored in the cloud or exploit cloud services without being noticed by legitimate users. The duration of these attacks allows hackers to adapt to security measures against them. Once unauthorized access is established, hackers can move through data center networks and use network traffic for their malicious activity.
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