User education won’t prevent a user from visiting a legitimate website that has been temporarily compromised to serve malicious content as part of a ‘drive by download’, ‘watering hole’ or ‘strategic web compromise’, including where malvertising runs malicious software without requiring user interaction. Working with invested partners. Such education might reduce the level of user resistance to the implementation of mitigation strategies. ", And according to "Stay Smart Online" the average cost of a cybercrime attack to a small business in Australia is $276,323.00. However, to prevent and automatically detect an attempted compromise, implementing a technical mitigation strategy (such as application control configured to log and report violations) is preferable to relying on user education. Test the data restoration process to verify that the backups are comprehensive and that data can be restored successfully. For example, users might be less likely to resist the removal of their unnecessary administrative privileges if they understand why the mitigation strategy is required. HIDS/HIPS uses behaviour-based detection capabilities instead of relying on the use of signatures, enabling organisations to detect malware that has yet to be identified by the cyber security community. Preferably block all executable content by default and use a process to enable selected users to access specific executable content if a business justification exists. Preferably also capture traffic from the network perimeter, noting that its usefulness is diminished if exfiltrated data is encrypted and sent to a computer that probably can’t be attributed to adversaries. unneeded/unauthorised RDP and SMB/NetBIOS traffic). Security Control: 1175; Revision: 3; Updated: Sep-18; Applicability: O, P, S, TS. Patch or mitigate computers exposed to ‘extreme risk’ security vulnerabilities within 48 hours of the security vulnerability being identified. Additionally, adversaries might scatter USB flash storage devices, CDs and DVDs containing malicious content in the car park of targeted users. This step is important for attackers to install payloads on target networks which may be otherwise not vulnerable through the exploitation of public-facing applications, to establish persistence through command and control systems, escalate privileges and even encrypt filesystems for ransom. If there are no complaints of broken functionality within a day, the patch is then deployed to all other user computers. Full restoration of backups is tested at least once when initially implemented, and each time fundamental information technology infrastructure changes occur. Security Control: 1512; Revision: 0; Updated: Sep-18; Applicability: O, P, S, TS. Initial Access – Exploit Public-Facing Application, Remove any unsupported or abandoned applications. an increased proportion of spear phishing emails and other indicators of malicious activity that users detect and report to the organisation’s IT security team. TLS encryption between email servers to help prevent legitimate emails being intercepted and subsequently leveraged for social engineering. contractual timely onsite vendor support to repair and replace damaged computers and network devices such as switches, routers and IP-based telephones. Implementing application control on important servers such as Active Directory, email servers, and other servers handling user authentication can help prevent adversaries from running malware that obtains passphrase hashes or otherwise provides adversaries with additional privileges. Partial restoration of backups is tested on a quarterly or more frequent basis. This mitigation strategy helps to identify and block the exfiltration of sensitive organisational data. Maintain, monitor and apply application updates regularly with a recommendation of 48 hours to fix an 'extreme risk' vulnerability. Relevant ISM Controls: Security Control: 1494; Revision: 0; Updated: Sep-18; Applicability: O, P, S, TS. Security-Enhanced Linux (SELinux) and grsecurity are examples of exploit mitigation mechanisms for Linux operating systems. Patch/mitigate computers (including network devices) with 'extreme risk' vulnerabilities within 48 hours. email, writing documents and web browsing) and are designed to be in production typically for one to three years before being refreshed, with regular opportunities for scheduled outages. Continuous incident detection and response with automated immediate analysis of centralised time-synchronised logs of allowed and denied computer events, authentication, file access and network activity. Additionally, adversaries use legitimate websites, which are required for business purposes, for malware delivery, command and control, and data exfiltration. Furthermore, a robust policy and processes should be used to enable data to be transferred from the virtualised environment to the user’s local environment. Organisations using operating system virtualisation, (especially third party) cloud computing infrastructure, or providing users with BYOD or remote access to the organisation’s network, might require controls that are less dependent on the physical architecture of the network. Ransomware can prevent computers from functioning, for example if operating system files or configuration data are encrypted. Focus on the highest priority systems and data to recover. Paying for cyber insurance isn’t a substitute for investing in cyber security protection by implementing these mitigation strategies, although cyber insurance might encourage organisations to implement these mitigation strategies to reduce the cost of their cyber insurance premium. Additional information is provided in this document to help organisations mitigate cyber security incidents caused by: Readers are strongly encouraged to visit the ACSC’s website [1] for the latest version of this document and additional information about implementing the mitigation strategies. Focus on users who are underperforming, about to be terminated or who intend to resign. Several of these alternative approaches assume that normal behaviour of users and computers can be accurately baselined to identify anomalies while avoiding false positives. Microsoft's latest recommended block rules are implemented to prevent application control bypasses. Mitigation guidance for OT environments includes: Mitigation guidance for IT environments includes implementing the mitigation strategies listed in the Strategies to Mitigate Cyber Security Incidents for both targeted cyber intrusions as well as for ransomware and external adversaries with destructive intent, especially focusing on the computers that administer OT environments, develop software for OT environments, or otherwise can interact with OT environments. An automated mechanism is used to confirm and record that deployed application and driver patches or updates have been installed, applied successfully and remain in place. Why does it exist? Furthermore, web browser ‘click-to-play’ functionality provides limited mitigation since it relies on users to make correct security decisions. Enforce the macro security configuration settings via Group Policy to prevent users from changing them to run a malicious or otherwise unapproved macro. The ACSC is aware of some spear phishing emails that use clever tradecraft and are believable such that no amount of user education would have helped to prevent or detect a compromise. For some vendor applications, upgrading to the latest version is the only way to patch a security vulnerability. Additionally, note that installing new software can create subdirectories in allowed paths that provide users (and therefore malware) with write and execute permissions, enabling arbitrary unapproved or malicious programs to run. This includes deleting or corrupting user data, applications, operating system files, boot firmware accessed via BIOS/UEFI and other firmware, or configuration settings of computers and other network devices which prevent them from booting their operating system or otherwise operating normally. process injection, keystroke logging, driver loading and persistence). the ability to quickly restore compromised computers and network devices to a known clean state. Furthermore, adversaries could use a stolen passphrase to access the user’s network drives once any other user who has access to the organisation’s corporate network has been remotely compromised. An overview of hunting to discover cyber security incidents is available at: Network-based intrusion detection/prevention system (NIDS/NIPS) using signatures and heuristics to identify anomalous traffic both internally and crossing network perimeter boundaries. Security Control: 1487; Revision: 0; Updated: Sep-18; Applicability: O, P, S, TS. Ransomware denies access to data, typically by encrypting it, until a monetary ransom is paid within a specified time period. An effective web content filter reduces the security risk of malware being accessed, as well as making it more difficult for adversaries to communicate with their malware. Daily backups are crucial for recovery from data-loss situations such as malware (particularly ransomware) infection, system crashes, hardware failures and destruction by malicious attackers. Security Control: 1144; Revision: 9; Updated: Sep-18; Applicability: O, P, S, TS. Microsoft note that their Microsoft Windows 10 operating system and Edge web browser natively implement many of EMET’s features and mitigations, making EMET less relevant for Microsoft Windows 10. manipulating network traffic using approaches historically used to evade network-based intrusion detection/prevention systems. Security Control: 0304; Revision: 5; Updated: Sep-18; Applicability: O, P, S, TS. It might be easily copied by adversaries without requiring administrative privileges. In the absence of a DMARC DNS record, the ACSC responded to a cyber security incident involving a major free webmail provider that delivered a spoofed email to the recipient’s inbox even though the email failed SPF checks. The effectiveness of network-based mitigation strategies continues to decrease due to evolutions in the architecture of IT infrastructure. The ACSC urges organisations to exercise caution when using publisher certificate rules to allow operating system files and other applications to execute. An appropriately configured implementation of application control helps to prevent the undesired execution of software regardless of whether the software was downloaded from a website, clicked on as an email attachment or introduced via CD/DVD/USB removable storage media. Security Control: 1500; Revision: 0; Updated: Sep-18; Applicability: O, P, S, TS. Every day new vulnerabilities and exploits are uncovered and software vendors are continuously issuing patches to … Preferably archive PDF and Microsoft Office attachments, and scan them again for malware every month for several months. Refer to the implementation guidance provided for mitigation strategy ‘Patch applications’. Important logs include DNS, web proxy logs containing connection details including User-Agent values, DHCP leases, firewall logs detailing network traffic entering and leaving the organisation’s network as well as logs of (especially outbound) blocked network traffic, and metadata such as Network Flow data. data transfers to unapproved cloud computing services including personal webmail, as well as the use of unapproved VPNs from the organisation’s network. Configure the Credential Guard feature in Microsoft Windows 10 and Microsoft Windows Server 2016, noting Microsoft’s stated limitations of this feature including it doesn’t protect the Active Directory database running on Microsoft Windows Server 2016 domain controllers, and it doesn’t prevent adversaries with malware running on a computer from using the privileges associated with any credential [35]. Prioritize cybersecurity risks. ‘Business email compromise’ involves adversaries using social engineering or targeted cyber intrusion techniques to abuse the trust in the target organisation’s business processes with the typical goal of committing fraud. Further guidance on securing content management systems is available at Patch operating systems. Three months later, the organisation’s IT staff realised that thousands of files needed for legal proceedings and stored on a network drive (file share) had also been encrypted by the ransomware. Cybersecurity awareness training – improve the ability for staff to identify and react accordingly to potentially malicious files. Technical security controls are used to prevent privileged users from reading emails, browsing the web and obtaining files via online services. Server application hardening helps the organisation to conduct its business with a reduced security risk of malicious data access, theft, exposure, corruption and loss. Why: To ensure information can be accessed and recovered following a cybersecurity incident (e.g. It also helps to mitigate adversaries using malicious content in an attempt to evade application control by either exploiting an application’s legitimate functionality, or exploiting a security vulnerability for which a vendor patch is unavailable. For example, after fully testing and understanding application control to avoid false positives, one approach is to deploy application control to the computers used by senior executives and their executive assistants. The use of IPsec authentication can ensure that a specific network port or ports on a sensitive server can only be accessed by specific computers such as those computers belonging to administrators. something the user is, such as their fingerprint or iris. Use Sender Policy Framework (SPF) or Sender ID to check incoming emails. Configure ASLR for all operating system programs and other software applications that support ASLR. Using removable storage media and connected devices in a controlled and accountable manner reduces the security risk of malware execution and unauthorised data exposure. uninstall Java if there is no business requirement to use it, configure Java to disable ‘Java content in the browser’, use a modern web browser which forbids running deprecated Java plugins, apply web browser specific configuration settings that disable Java in the web browser, use a separate web browser that can only run Java code located on the organisation’s internal systems. The effect of this is that the attack surface and management required for updates are reduced. Regarding this guidance you can contact us via 1300 CYBER1 ( 1300 292 371 ) or:. Device’ ( BYOD ) and grsecurity are examples of system behaviour logs and other accounts allow. Mail ( DKIM ) be inspected such as routers, switches and firewalls, and each fundamental... 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