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PROTECTING DATA FROM RANSOMWAREAND OTHER DATA LOSS EVENTSA Guide for Managed Service Providers to Conduct, Maintain and Test Backup FilesOVERVIEWThe National Cybersecurity Center of Excellence (NCCoE) at the National Institute of Standards and Technology(NIST) developed this publication to help managed service providers (MSPs) improve their cybersecurity and thecybersecurity of their customers. MSPs have become an attractive target for cyber criminals. When an MSP isvulnerable its customers are vulnerable as well. Often, attacks take the form of ransomware.Data loss incidents—whether a ransomware attack, hardware failure, or accidental or intentional datadestruction—can have catastrophic effects on MSPs and their customers. This document provides recommendations to help MSPs conduct, maintain, and test backup files in order to reduce the impact of these data lossincidents. A backup file is a copy of files and programs made to facilitate recovery. The recommendationssupport practical, effective, and efficient back-up plans that address the NIST Cybersecurity FrameworkSubcategory PR.IP-4: Backups of information are conducted, maintained, and tested. An organization does notneed to adopt all of the recommendations, only those applicable to its unique needs.This document provides a broad set of recommendations to help an MSP determine: items to consider when planning backups and buying a backup service/product issues to consider to maximize the chance that the backup files are useful and available when needed issues to consider regarding business disaster recoveryCHALLENGEAPPROACHBackup systems implemented and not tested orplanned increase operational risk for MSPs. Theimpacts of data loss events can include one or moreof the following:NIST Interagency Report 7621 Rev. 1, Small BusinessInformation Security reinforces the need for file backups to enable businesses to “resume normal operations after an event." To help small businesses, andthe MSPs that support them, effectively conduct,maintain and test backup files, the NCCoE identifiedcapabilities that mitigate the risks identified in theChallenge section. Each MSP should consider thebusiness value or dependence it has on the data itcontrols to determine the appropriate capabilities. Inaddition, if the MSP is storing customer data(operational or backups), it should take into accountany customer data retention requirements. loss of productivity revenue/customer loss negative reputation and brand impacts1

National Institute of Standards and TechnologyRECOMMENDATIONS (Planning, Implementations, Testing)PLANNINGPlanning is an iterative process critical to help an organization optimize and balance costs and operationalneeds. The following recommendations are based on guidance from NIST Special Publication (SP) 800-53,Rev 4, for controls CP-2, Contingency Planning; and CP-9, Contingency Planning-Information System Backup.When creating a backup plan the following considerations and operational issues should be addressed: Identify the files to back up. Prioritize files based on business value. For example, an organization maynot be able to backup all files due to cost, size, or accessibility. Examples of key files are event logs, userfiles, and applications. See NIST SP 800-53, Rev. 4, AU-9, Protection of Audit information, for moreinformation.{{Various cloud services may require different backup techniques. For example, the data backuptechnique for an office collaboration platform may differ from a customer relationship management(CRM) service. In some cases, the data may not be readily available to back up. In those cases, analternative approach may be required.{{Customer data files stored by an MSP may need to be backed up. Consider the customer file retentionpolicies and prioritization needs. Determine restoration time. Establish the desired timeframe to restore files and applications to minimize negative impacts to the organization’s mission or business operations–known as recovery timeobjective (RTO).{{Issues that may impact the ability to meet RTO include the internet bandwidth available, any off-sitebackup facility bandwidth, file transfer limitations and hardware file transfer limitations. Determine file backup timing. Determine maximum age of the backup files to enable operations to bereestablished with minimum acceptable interruption of operations–known as the recovery pointobjective (RPO). Acceptable backup file age may vary based on the file types and business processimpacted (operations, human resources, accounting, for example). Determine the relationships among systems to understand any dependencies or order of restorationrequirements. Determine what set of backup files and other information need to be secured offline and the updateintervals that satisfy the RPO and RTO for those files. This data and information may includepasswords, digital certificates, encryption keys, and other information needed to reestablish businessoperations quickly. Plan to save more than one backup file to safeguard your information. (See United States ComputerEmergency Readiness Team backup recommendations){{To increase the chances of recovering lost or corrupted data, follow the 3-2-1 rule:3 – Keep three copies of any important file: one primary and two backups.2 – Keep the files on two different media types to protect against different types of hazards.1 – Store one copy – or “go bag” – off-site (e.g., outside the home or business facility). Develop response and recovery processes and procedures that utilize the backup files and backupsystems. See Section 5 of NIST SP 800-184 Guide for Cybersecurity Event Recovery for additionalrecommendations.2

National Cybersecurit y Center of Excellence Determine the appropriate technical approach to generating backups (automation, manual processes).{{See the Capabilities section below for a discussion of the type of backup technologies that may beconsidered.{{Printed copies of some data/files may be sufficient as well as secure. Determine workplace relocation options. Fire, flood, or other catastrophic events could require temporaryor permanent office relocation, and not all backup capabilities will be portable. See NIST SP 800-53 Rev 4,SC-37 Out-of-Band Channels, for more information. See offline backup recommendation above. Identify any regulatory and legal data retention requirements such as chain of custody, that may affect thebackup plan and technical approach. See NIST SP 800-86 for additional information regarding forensictechniques.{{Be sure to identify customer files/data retention and care requirements, ensuring that those withRPO/RTO and/or specific custody/retention requirements are treated appropriately. Test the planning for recovery for both individuals and the entire organization. See Section 3.3 of NIST SP800-184, Guide for Cybersecurity Event Recovery, for plan recommendations.IMPLEMENTATION RECOMMENDATIONS Integrate the appropriate technologies into the operation (noted in Capabilities and Technologies sectionbelow). Keep a set of systems completely disconnected from the business network (offline or on a separate/firewalled network or located outside the office) for use during a recover/emergency situation. Prepare a “Go Bag” for data recovery. Keep a copy of critical data–including passwords and security keys,in a separate, secure and accessible location to facilitate recovery operations in the event of a data lossincident. Paper copies of some data may be necessary.{{Be sure to retain credentials for cloud-hosting providers in printed format and/or electronic forms off-siteand offline, such as cloud service authentication personal identification numbers, encryption keys and webbrowser cookies. Physical diversity capability. Consider an alternative recovery site in case the primary facility is unavailablefor recovery activitiesTESTING/MONITORING Test (both manual and automated) the response and recovery processes, procedures and technologies to:{{verify backup file integrity{{ensure effectiveness and efficiency of recovery processes and procedures{{develop lessons learned. Lessons learned from tests may include:time to retrieve files from off-site (cloud or data center across the internet)‒{ whether file retrieval time is directly related to file sizes‒{ time to restore files to systems,‒{ time to rebuild systems,‒{ degree of understanding regarding the responsibilities and authorities among the personnel involved.‒{ effectiveness of the processes and procedures‒{3

National Institute of Standards and Technologyidentification of gaps (technical and procedural){{conduct automated testing that may include testing the various aspects of the backup technologiessuch as automated restoration, file recovery, and network connectivity{{provide similar lessons through tabletop test exercises Monitor (both manual and automated) the backup systems and files to:{{ensure backup files are created{{ensure backup files can be successfully recovered and are usable{{monitor automated testing for success/failure enables proactive management.‒{CAPABILITIES AND TECHNOLOGIESTo effectively conduct, maintain and test backup files to reduce the impact of data loss incidents, considerthe following capabilities: Storage technologies{{Cloud storage is a service offered to enable off-site file storage (internet connected) in a managedfacility and information technology (IT) infrastructure. This may include services such as virtualshared drives or offline updatable storage along with encryption, regulatory compliance, backupfrom/to anywhere, and redundant file storage. However, cloud storage may identify dependenciessuch as file download capacity limitations, internet access (availability, bandwidth), and restorationtime limitations, as well as lack of geographic location control which may affect domestic andinternational regulatory compliance.{{Local hard drive storage includes server storage typically included in the operational IT infrastructurenetwork or devices physically attached to the workstations and/or servers. Options may includewrite once read many (WORM) drives, and universal serial bus (USB) drives, as well as networksegmentation to restrict access to the backup files. However, planning for local storage mayidentify dependencies such as lack of location/physical diversity, hardware and software failuremanagement and software patch management.{{WORM storage includes non-rewriteable technology such as compact disk (CD), digital versatile disk(DVD), and specialized solid-state drive. Files/data written to these types of drives cannot bemodified, providing effective file/data protection at the hardware level. However, planning forWORM storage may identify dependencies, including susceptibility to the same physical risks as otherIT hardware, and the need to store/protect the devices securely and manage them appropriately.{{Removable media storage includes hard drives, solid state drives, CDs and DVDs (rewritable andnonrewritable), USB (thumb drives), and magnetic tape. Planning for removable media storage mayidentify dependencies similar to on-site and WORM storage. Removable media storage may alsoapply to use with a go bag as described above. Automated backup systemEndpoint, servers, cloud services, and network based – these capabilities include agent and agentlesssystems as well as on-premises and cloud-based backup capabilities. Planning for automated backupsystems may identify dependencies similar to local storage and cloud storage.4

National Cybersecurit y Center of Excellence Encryption and key managementEncryption is recommended for data at rest and data in transit to prevent disclosure of data (inadvertent ormalicious). Encryption technologies include disk encryption, data file encryption typically included in dataloss prevention, and data transmission using Transport Layer Service and HTTPS. Planning for file/dataencryption may identify dependencies such as encryption key management to prevent file/data loss.Encryption key management includes controlling use and access to the encryption keys for the life of anyencrypted files. Refer to the Recommendation for Key Management, NIST SP 800-57, Part 1, Sections 5.1,5.2, and 8 for additional information regarding encryption key management; sections 6.2, 8.2.2, and 9.5 forencryption key storage management; and section 9.4 for encryption key backup recommendations. Part 2and Part 3 of NIST SP 800-57 provide additional details on organizational and application specific keymanagement. Cloud-based backup service providersThese capabilities provide backup file storage in each vendor’s cloud/data center(s), for example. Theservices may include on-premises appliances, agent or agentless techniques to identify files to be stored forbackup, such as frequency; data type, full or incremental; and various levels of security (encryption,geographic diver-sity). Planning for cloud-based backup services may identify dependencies similar to cloudstorage. Backup of data processed in cloud servicesThe capabilities provide backup file storage for the data maintained within each cloud service. Planning forcloud service data backup may identify dependencies similar to cloud storage. A combination of the capabilities listed above may be required to backup data/files stored in cloud services. The combination may bedetermined on a case-by-case basis.The following NIST publications describe solutions and implementation guides that include the capabilities listedabove: NIST SP 1800-11, Data Integrity: Recovering from Ransomware and Other Destructive Events NIST SP 1800-25, Identifying and Protecting Assets Against Ransomware and Other Destructive Events NIST SP 1800-26, Detecting and Responding to Ransomware and Other Destructive EventsARCHITECTUREThe diagram below illustrates a typical MSP IT infrastructure (including cloud services utilized by MSPs) andhighlights where the capabilitie