Securing Sharepoint In The Cloud From Data Breaches
Understanding SharePoint Security Risks in the Cloud
As organizations move their SharePoint environments to the cloud, they expose their data to new threats. Cloud-based SharePoint instances face risks including data breaches, compromised accounts, denial-of-service attacks, misconfigured storage, and vulnerabilities stemming from the multi-tenant nature of cloud platforms.
Data breaches remain one of the most significant risks facing SharePoint users in the cloud. Threat actors use techniques like phishing, brute force attacks, and exploitation of vulnerabilities to gain unauthorized access to sensitive SharePoint libraries and lists. Once inside, they can exfiltrate confidential files and emails to sell or publish online.
Compromised accounts with excessive privileges represent another common threat vector. An attacker who gains control of a site collection administrator or tenant administrator account can potentially access all files across a SharePoint cloud environment. Without proper access controls and monitoring, the compromise may go undetected allowing the bad actor to inflict substantial damage.
Denial-of-service (DoS) attacks also endanger availability by flooding sites and services with malicious traffic. SharePoint Online uses load balancing and geo-distributed infrastructure to minimize downtime from DoS events. However, a large enough attack can still render SharePoint cloud environments inaccessible to legitimate users.
Misconfigurations in cloud storage pose a distinct set of risks…
Multi-tenancy introduces vulnerabilities as well since cloud providers host multiple customers on shared infrastructure. Noisy neighbors who overconsume resources or flaws in the hypervisor can create security issues that impact all tenants.
Best Practices for Securing SharePoint Cloud Deployments
Securing SharePoint Online and hybrid environments requires a multilayered approach covering identity, access, encryption, monitoring, and general security hygiene. Recommended practices include:
- Enabling multi-factor authentication (MFA)
- Using role-based access control (RBAC)
- Configuring storage encryption
- Setting up audit logging and alerts
- Isolating test and production environments
MFA adds an extra layer of identity assurance by requiring users to present two forms of verification such as a one-time code sent via SMS in combination with a password. Mandating MFA for all administrative logins makes compromise of those sensitive accounts drastically harder.
RBAC restricts users’ capabilities based on their roles within the organization. Rather than granting blanket access, RBAC provisions the minimum privileges needed to fulfill duties. For example, most users require read/write permissions to certain libraries and sites rather than unrestricted control across the tenant.
Enabling BitLocker or another encrypted file system on SharePoint cloud storage significantly reduces the business impact should an attacker successfully exfiltrate content. While the criminal maintains possession of the files, encryption renders the data unreadable without the proper cryptographic keys.
Auditing tracks critical events like file accesses and permission changes while alerts notify administrators about suspicious activity. Together, logs and alerts provide monitoring and visibility to detect attacks as they unfold rather than after data loss or destruction.
Separating SharePoint test and production avoids accidentally exposing confidential data…
Detecting and Responding to SharePoint Cloud Data Breaches
Despite taking precautions, SharePoint cloud breaches still occur requiring an effective incident response plan to investigate, remediate, and enhance defenses.
Warning signs of a potential breach include unauthorized file operations like mass downloads or deletions, spikes in outbound data transfers, and audit logs detailing compromised credentials. Anomalous activity, particularly during off-hours, should prompt further scrutiny.
Upon discovering indicators, the first step involves confirming whether an actual compromise transpired. Forensic examination of file access logs and permissions changes can prove useful when piecing together what happened.
With evidence in hand, the response shifts to containment. Potential actions consist of forcing password resets for high-privilege accounts, temporarily disabling site collections, and blocking suspicious IP addresses.
Longer term, organizations must identify and remediate vulnerabilities that facilitated the breach whether technical misconfigurations, deficient policies, or user security awareness gaps. This serves to improve defenses and prevent repeat incidents.
Example Code for Enabling SharePoint Storage Encryption
Mandating storage encryption provides an added safeguard should SharePoint libraries and lists fall into malicious hands.
Set-SPOTenant -EnableTenantStorageEncryption $true
This PowerShell command enables BitLocker encryption across SharePoint Online document libraries, media files, and other unstructured data at rest.
Key Takeaways for Keeping SharePoint Cloud Data Safe
Defending SharePoint Online against breaches takes a multilayer approach spanning preventative controls, ongoing monitoring, and planning for the inevitable incidents.
Preventative capabilities like MFA, RBAC, and encryption make exploitation vastly more difficult while auditing and alerts enable rapid detection of threats.
Once breached, organizations must have an incident response plan detailing containment, eradication, and recovery activities. Learnings then feed back into enhancing defenses and user education.
By leveraging cloud security best practices, securing SharePoint in multi-tenant environments proves eminently manageable though still requiring vigilance and continuous adaptation as the threat landscape evolves.
