Network segmentation. Patch/mitigate computers (including network devices) with 'extreme risk' vulnerabilities within 48 hours. The CISO and CRO have vital roles in making sure their organization is ready to prevent, detect and respond to cyber incidents … whether the product generates enough useful data to enable cyber security incidents to be identified, without causing too many false positives which overwhelm the organisation’s incident response team. Relevant ISM Controls: Security Control: 1494; Revision: 0; Updated: Sep-18; Applicability: O, P, S, TS. In contrast, the appropriate use of multi-factor authentication helps to hinder adversaries, especially if implemented for remote access, as well as for when users perform privileged actions such as administering a computer, and for when users access an important (sensitive or high-availability) data repository. Domain-based Message Authentication, Reporting and Conformance (DMARC) enables a domain owner to specify a policy stating what action the recipient’s email server should take if it receives an email that has failed an SPF check and/or a DKIM check. There are a variety of approaches to deploying patches to applications and operating systems running on user computers, based on the organisation’s risk tolerance, as well as how many applications the organisation uses where the applications are legacy, unsupported, developed in-house or poorly designed. Such users are Most Likely Targets who usually run a limited number of software applications such as Microsoft Office, an email program and a web browser. Block and log outgoing emails with sensitive keywords or data patterns deemed to be too sensitive for the recipient’s email address. What is the Essential 8? The mitigation strategies can … Adversaries often use zip, RAR or other archive files to compress and encrypt a copy of the organisation’s sensitive data. Mitigation guidance for ‘business email compromise’ includes: Industrial control systems (ICS) leverage operational technology (OT) environments, which include components such as electronic sensors as well as systems such as networked computing hardware. Essential . Alternatively, adversaries might use a keystroke logger or the ‘pass the hash’ technique, avoiding the need to crack passphrase hashes. Use Sender Policy Framework (SPF) or Sender ID to check incoming emails. After performing testing to confirm that there is no significant business impact, deny typical low-privileged users the ability to run all script execution engines shipped with Microsoft Windows including Windows Script Host (cscript.exe and wscript.exe which run JScript and VBScript including Windows Script Files), powershell.exe, powershell_ise.exe, cmd.exe, wmic.exe and where possible Microsoft HTML Application Host (mshta.exe). administrative accounts that allow vendors to perform remote access. Threat intelligence assists with the hunting process, though organisations should critically assess whether an external threat intelligence feed is of value, based on whether: As an example of actual threat intelligence consisting of more than just indicators of compromise, the ACSC provided an Australian organisation with threat intelligence about a specific adversary who was likely to send spear phishing emails to the organisation’s employees during a specified one-month date range to obtain data about a specific topic. Cyber security incidents often involve the use of ‘dynamic’ domains and other domains provided free to anonymous internet users, due to the lack of attribution. Organisational executives and management can reduce some motivations for employees to become malicious insiders by facilitating a culture of appreciated and engaged employees who have fair remuneration and merit-based career advancement opportunities. Security Control: 1544; Revision: 1; Updated: Apr-20; Applicability: O, P, S, TS. This typically isn’t a viable low-risk exfiltration option for a targeted cyber intrusion where adversaries are in a physically distant location such as a foreign country. 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. Note the exception for regsvr32.exe and rundll32.exe – these are required for legitimate functionality but can be abused to circumvent application control, which can be mitigated by configuring rules in Microsoft’s Enhanced Mitigation Experience Toolkit (EMET). Otherwise if every new file is hashed, the list of hashes is likely to become too large and if distributed via Group Policy, might unacceptably slow down users logging into their computers. In addition to configuring system-wide EMET rules, configure EMET rules for applications that interact with potentially untrusted content, for example web browsers, Microsoft Office and PDF viewers. Maintain, monitor and apply application updates regularly with a recommendation of 48 hours to fix an 'extreme risk' vulnerability. is able to decrypt and perform analysis of email and web content that was encrypted by SSL/TLS when in transit over the internet, analyses emails before delivering them to users, to avoid users being exposed to malicious content, rapidly and effectively mitigates web content that has already been delivered to users and has subsequently been identified as malicious – mitigation might include blocking the user’s computer from having access to the internet infrastructure that the malicious content communicates with, or otherwise quarantining the user’s computer. Red Piranha information is also available on Facebook, Twitter, and LinkedIn. 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. Organisations can conservatively deploy DMARC if they are concerned about legitimate emails sent from their domain being incorrectly rejected. Vendor products increasingly advertise alternative approaches to determine whether applications, network communication, computer behaviour or associated logs exhibit indications of malicious activity. A recent backup of data and proven data restoration process are vital to mitigate data being encrypted, corrupted or deleted by ransomware or other destructive malware, malicious insiders, accidental mistakes by users, or non-malicious failure of storage hardware due to a range of causes including faulty equipment, wear, power outage, fire or flood. Along with this, privileged accounts (such as SYSTEM, Administrator or root) should not be used for any activities outside their intended purpose, such as web browsing or reading emails. Reject incoming emails that have the organisation’s domain as the email sender but do not originate from email servers approved by the organisation. HTTP/HTTPS sessions with an unusual ratio of outgoing traffic to incoming traffic, HTTP/HTTPS traffic with a ‘User-Agent’ header value that is not associated with legitimate software used by the organisation, DNS lookups for domain names that don’t exist and aren’t an obvious user typo, indicating malware communicating to a domain that is yet to be registered by adversaries, DNS lookups for domain names that resolve to a localhost IP address such as 127.0.0.1, indicating malware that adversaries are not ready to communicate with, use of removable storage media and connected devices especially USB storage devices, data access and printing which is excessive compared to the normal baseline for a user and their peer colleagues. When a targeted cyber intrusion is identified, it needs to be understood to a reasonable extent prior to remediation. Applications such as web browsers [36] [37] and PDF viewers [38] from some vendors include such an inbuilt sandbox. A frequently used technique by attackers to encourage users to execute the code is to place what appears to be a genuine Microsoft message instructing the user to enable Add-ins, content and/or editing. 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. Such compromises might occur by adversaries sending spear phishing emails, by exploiting security vulnerabilities in internet-accessible computers such as websites and associated databases, or by using brute-force passphrase guessing to remotely access computers exposed to the internet via Remote Desktop Protocol (RDP). Regularly test the organisation’s incident response plan, processes and technical capabilities. Operating system hardening (including for network devices) based on a Standard Operating Environment (SOE), disabling unneeded functionality (e.g. Some jump servers might require limited internet access if they are used to administer defined computers located outside of the organisation’s local network. Enforcing proper management of privileged accounts mitigates several common adversary techniques such as account manipulation, credential dumping, exploitation of remote services, pass the hash, process injection and service execution. Another common method of initial compromise, more commonly seen in targeted attacks but also seen with increasing frequency in automated attacks is the exploitation of public-facing applications. Don’t use Adobe Reader prior to version X, or unsupported Internet Explorer versions (currently version 10 and older) especially when accessing the internet. This mitigation strategy helps to identify and block the exfiltration of sensitive organisational data. Security Control: 1505; Revision: 0; Updated: Sep-18; Applicability: O, P, S, TS. Only allow trustworthy websites that require such web browser functionality for a specific business purpose, such as a legacy Flash application used on the organisation’s intranet. Such websites include web forums, social networking websites, cloud computing services, as well as legitimate but temporarily compromised websites. These evolutions also impact the ability to implement the mitigation strategy ‘Deny corporate computers direct internet connectivity’. Implementation guidance for associated mitigation strategies is provided later in this document, and a table summary of the associated mitigation strategies is provided in the complementary Strategies to Mitigate Cyber Security Incidents publication. Some organisations might choose to support selected websites that rely on advertising for revenue by enabling just their ads and potentially risking compromise. Restrict administrative privileges to operating systems and applications based on user duties. OLE), web browsers and PDF viewers. DMARC also contains a reporting feature which enables a domain owner to obtain some visibility of whether their domain is being spoofed in emails sent by adversaries. A different approach involving more thorough testing is usually used for deploying patches to servers, as well as for deploying upgrades that introduce significant additional features and capabilities. Ideally, an alternative corporately approved method of data transfer should be established which avoids the need to use removable storage media. Backups are stored for three months or greater. Configure the Microsoft Office File Validation and Protected View features to inspect and validate Microsoft Office files for potentially malicious abnormalities. Capturing network traffic can assist the organisation to determine the techniques used by adversaries, perform a damage assessment and assist with remediating the compromise. 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. One partial approach is to use applications that have been architected to run in an inbuilt sandbox, often leveraging operating system functionality to assist with the sandbox implementation. It can be found at https://www.cyber.gov.au/acsc/view-all-content/ism. Most software vendors provide updates and patches to applications with publicly identified vulnerabilities, with best practice being that a patch or update is made available before the vulnerability is disclosed to the public. The first control, and therefore the control considered the most important of the eight defined mitigation strategies, is the prevention of execution of unapproved/malicious applications. Restrict access based on the connectivity required, user job role, business function, trust boundaries and the extent to which data is important. Test the data restoration process to verify that the backups are comprehensive and that data can be restored successfully. User education needs to be tailored to the job role of the user. For the relatively small number of organisations where employees have access to highly classified data or other extremely sensitive data, a psychological assessment should be performed by qualified personnel to explore topics including allegiances and beliefs as well as character weaknesses which could be leveraged and manipulated by adversaries. Focus on the highest priority systems and data to recover. Installers often contain installation information as well as files to be installed all within one package. Use Credential Guard. Two of the top 4 strategies revolve around patching applications and operating systems. For Microsoft Windows operating systems prior to Microsoft Windows 8.1 and Microsoft Windows Server 2012 R2, ensure that Microsoft patch KB2871997 has been applied and configure the ‘UseLogonCredential’ Windows Registry value to 0 to help mitigate adversaries obtaining clear-text credentials stored in memory. Educate employees to lock their computer screen whenever they are away from their computer. Relevant ISM Controls: Security Control: 1511; Revision: 0; Updated: Sep-18; Applicability: O, P, S, TS. Relevant ISM controls: Security Control: 0843; Revision: 8; Updated: Apr-20; Applicability: O, P, S, TS. Prioritise patching security vulnerabilities in software used to interact with content from the internet, as well as software which runs with elevated privileges such as anti-malware software and third party video drivers. Some organisations might choose to support inbound network connections from anonymity networks to the organisation’s public internet-accessible websites, to cater to website visitors who wish to remain anonymous for privacy reasons. Stage 1 – Malicious software (malware) delivery and execution: The phrase ‘Most Likely Targets’ describes users who are most likely to be targeted as part of the first stage of a targeted cyber intrusion, and includes: Understanding the goals of adversaries can provide insight into which other users are likely to be targeted based on their access to sensitive data. Adversaries could use compromised account credentials, or in some cases exploitable security vulnerabilities affecting other computers in the organisation, to propagate (laterally move) throughout the network in order to locate and access sensitive data. The effectiveness of network-based mitigation strategies continues to decrease due to evolutions in the architecture of IT infrastructure. User education. 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]. Configure Microsoft Office macro settings to block macros from the internet, and only allow vetted macros either in ‘trusted locations’ with limited write access or digitally signed with a trusted certificate. ", And according to "Stay Smart Online" the average cost of a cybercrime attack to a small business in Australia is $276,323.00. Dynamic analysis uses behaviour-based detection capabilities instead of relying on the use of signatures, enabling the organisation to detect malware that has yet to be identified by the cyber security community. Perform timely log analysis focusing on connections and the amount of data transferred by Most Likely Targets to highlight abnormal internal network traffic such as suspicious reconnaissance enumeration of both network drives (file shares) and user data including honeytoken accounts. Use an automated mechanism to confirm and record that deployed patches have been installed, applied successfully and remain in place. Ensure an operating system patching process is in place. Capture network traffic to and from corporate computers storing important data or considered as critical assets, and network traffic traversing the network perimeter, to perform incident detection and analysis. Adversaries might change bank account numbers and contact details on invoices so that the adversaries are inadvertently paid [14]. Block/quarantine content that can’t be inspected such as passphrase-protected archive files (e.g. Security solutions, such as Microsoft Threat Protection, provide multiple layers of threat protection across data, applications, devices, and identities and can help protect your company from … Security Control: 1485; Revision: 0; Updated: Sep-18; Applicability: O, P, S, TS. TLS encryption between email servers to help prevent legitimate emails being intercepted and subsequently leveraged for social engineering. Why: The listed applications to be restricted are common vectors of initial compromise, used to deliver and execute malicious code on a system, along with this the management required for updates is reduced, saving time and money. There is an industry-standard dictionary for publicly disclosed vulnerabilities and exposures known as Common Vulnerabilities and Exposure (CVE) which is sponsored by the U.S. Department of Homeland Security Cybersecurity and Infrastructure Security Agency (CISA). Disable unneeded features in Microsoft Office (e.g. In such cases, activities such as application execution or network communication is denied by default and only activity explicitly approved of by system administrators and network administrators to meet business requirements is allowed to occur. 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. Analyse and action real-time log alerts generated by file activity monitoring tools to identify suspicious rapid and numerous file copying or changes. Alternatively, adversaries might compromise a legitimate website which the user is likely to visit, referred to as a ‘watering hole’ or ‘strategic web compromise’. Mitre ATT&CK for Enterprise: Mitigations – Disable or Remove Feature or Program, Establish a standard operating environment (SOE). When installing new software, avoid creating hashes for added files that aren’t of an executable nature. Configure web browsers to block Flash (ideally uninstall it if possible), advertisements and untrusted Java code on the internet. Host-based intrusion detection/prevention system (HIDS/HIPS) to identify anomalous behaviour during program execution (e.g. Patch or mitigate computers (including network devices) exposed to ‘extreme risk’ security vulnerabilities within 48 hours of the security vulnerability being identified. restrict network connectivity with IT environments and with the internet – noting that completely air gapping OT environments might be impractical, limit remote access from the internet, and where remote access is used implement network-level encryption such as a VPN, multi-factor authentication and a strong passphrase policy, ensure that only authorised code can be introduced to OT environments and run, by controlling removable storage media and connected devices, implementing application control where possible, and considering the use of code signing, use vendor-supported applications and operating systems, and patch associated security vulnerabilities in a timely manner as soon as possible within the constraints of system uptime requirements – note the lack of availability of patches for a proportion of security vulnerabilities specific to OT assets which are deemed too difficult to fix or the associated equipment is no longer supported by the vendor, refer to additional guidance available from US Government authorities, simply preventing a user from installing new applications to their computer’s hard disk, using a ‘next-generation’ firewall in an attempt to identify whether network traffic is generated by an approved application. Web browsers are configured to block java from the internet. The scarcity of unused and available publicly routable IPv4 address results in an increasing need for IPv6 to be used by computers that directly connect to the internet. 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. Due to the amount of time that had elapsed, the organisation’s backups contained encrypted copies of the files. Computers without a need to use removable storage media or connected devices can be configured to help prevent such connectivity by removing associated drivers from the operating system, using third party solutions to allow and block access to specific classes of devices, configuring computer BIOS/UEFI settings to disable access to associated hardware, and physically removing or disabling associated hardware used for external data storage or external device connectivity. Blocking unneeded/unauthorised network traffic reduces the attack surface of computers by limiting exposure to network services, as well as reducing the ability of adversaries to propagate throughout the organisation’s network. Backups are stored offline, or online but in a non-rewritable and non-erasable manner. Organisations need to regularly test and update their incident response plan, processes and technical capabilities, focusing on decreasing the duration of time taken to detect cyber security incidents and respond to them. As the current COVID-19 situation develops, organizations must reconsider preventive measures and actions to take should a cyber incident occur. When implementing this alternative approach, the mitigation strategy ‘Network segmentation’ should also be implemented to mitigate the security risk of a compromised virtualised environment accessing the organisation’s important data. This baseline has been created to allow organisations, particularly small to medium businesses to focus on improving security controls to reduce the risk of a cybersecurity incident occurring. It is advisable to deploy application control in phases, instead of trying to deploy it to an entire organisation at once. 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. Alternatively, adversaries could turn the organisation’s intranet website into a watering hole to compromise users when they visit. However, IPv6 might not be needed by computers on an organisation’s internal network which use IPv4 addresses in the reserved range. The use of single sign-on authentication in the organisation might significantly benefit adversaries. To help make the most of limited staff resources, leverage automation and context to focus on high priority security events and avoid false positives. How do I measure my businesses implementation? vCISO is a Virtual CISO which provides under contract the services from its resources, that would otherwise be performed by an in house CISO. Benefits of computers and network devices having a consistent managed SOE configuration include: Harden file and Windows Registry permissions, for example where possible, prevent users (and therefore malware running on the user’s behalf) from running system executables commonly used for malicious purposes as listed in mitigation strategies ‘Application control’ and ‘Continuous incident detection and response’. Require long complex passphrases. Disable Office add-ins. Web content filtering. Why: Security vulnerabilities in operating systems can be used to further the compromise of systems. Test the restoration process when the backup capability is initially implemented, annually and whenever IT infrastructure changes. Application control to prevent execution of unapproved/malicious programs including .exe, DLL, scripts (e.g. Ensure that application control prevents unapproved programs running regardless of their file extension. Furthermore, web browser ‘click-to-play’ functionality provides limited mitigation since it relies on users to make correct security decisions. system administrators performing configuration management and knowing what software is running on computers thereby facilitating implementing application control and patching security vulnerabilities, the ability to detect anomalous software running by monitoring for deviations from the standard baseline – implementing application control, even if configured in ‘audit’/’logging only’ mode, can provide this ability, network administrators knowing what software is running on network devices thereby facilitating patching security vulnerabilities, as well as knowing what software is allowed to communicate on the network thereby facilitating baselining expected network activity. ongoing vetting especially for users with privileged access, immediately disable all accounts (especially remote access accounts) of departing users, and remind users of their security obligations and penalties. Personnel management assists to avoid employees having malicious intent, developing malicious intent, or carrying out their malicious intentions undiscovered until after damage has been done. Microsoft developed a free tool called ‘Local Administrator Password Solution’ (LAPS) to periodically change the passphrase of the local administrator account on every Microsoft Windows computer in the domain to a random value. When deciding on how to implement Security for your business, it is critical to adopt a risk management framework, and there are many which often vary by industry. Data Execution Prevention (DEP), Address Space Layout Randomisation (ASLR) and Enhanced Mitigation Experience Toolkit (EMET) [28]. something the user is, such as their fingerprint or iris. something the user knows, such as a passphrase or PIN, something the user has, such as a physical token or software-based certificate. Such persistence involves malware attempting to persist after the computer is rebooted, for example by modifying or adding Windows Registry settings and files such as computer services. the organisation has already implemented mitigation strategies that have higher security effectiveness including ‘Continuous incident detection and response’, and leverages logs and threat intelligence already available to the organisation, the organisation has the staff resources and the IT infrastructure capability to consume and action the threat intelligence, the threat intelligence consists of more than simply domains, IP addresses, file hashes and other indicators of compromise which are similar to reactive signatures and have little relevance if changed regularly or per victim, the threat intelligence has context and ideally is tailored to the organisation (or at least to their business sector/industry) to provide a high signal-to-noise ratio with negligible false positives. 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