As published at: https://informationsecuritybuzz.com/articles/the-business-value-of-cyber-resilience/
Scrutiny over data protection and privacy, and the reporting and analysis behind a powerful threat defense, is moving to the boardroom as organizations are seeing the need to take a closer look at just how effective their security posture is. In a report, Gartner labels it ‘A New Era of Risk Reporting to the Board,’ noting that “Board members are increasingly aware and concerned about the importance of information security.” Gartner also notes that discussions have evolved from standard security metrics to understanding the enterprise-wide ramifications of information security risks.
Boards are now expecting analysis and reporting of the organization’s cyber resilience at the same level as other formal mandatory reporting and company controls. However, executing a cyber resilience strategy is easier said than done, particularly for small or mid-sized businesses that do not have the skills or expertise in house, or large organizations that are dealing with legacy or complex, interconnected business models.
Aligning Controls with the Threat Landscape
Historically, security controls used to monitor the output and efficiency of a company have been traditionally based around the areas of policy, process procedures and management, along with technical, physical and personnel metrics. In today’s world of constant cyber threats, although these areas are still valid, they must be reinforced with the ability to consider the context of the controls in relation to threats to which the organisation is exposed. This context is provided by the results of cyber incident responses, the exchange of cyber-attack information via information exchanges, CERTS (Computer Emergency Response Teams) and the fast-emerging threat intelligence industry.
The additional information provides the ability to review and consider all the controls in the context of the current threat landscape. Then, it is possible to justify new spend to deploy appropriate controls to further mitigate risk. For the first time, the availability of this almost real-time threat information allows security teams to react to a change in threat and prevent a breach. This is a better response strategy rather than waiting for a successful attack or simply trying to contain a threat once the network flags anomalous behavior.
Although an abundance of information is becoming available on how to protect a business, the issue is: what is considered as effective and can demonstrate that the business has taken the appropriate action to protect itself and any personal data? Analyzing security options from this perspective of corporate governance will form the basis for building a cyber security resilient operation.
An example of why this is important has been the growth of controls covering health and safety. Mandatory compliance regulations and reporting are now standard practice. Should there be a serious health and safety issue the mandatory reports are used to provide evidence of best practices and help demonstrate compliance. This has not only helped to protect people but has also become part of the corporate culture.
Taking Corporate Responsibility for Cyber Resilience
Assessing the business value of cyber resilience comes in several forms. A privacy breach, for example, can damage customer goodwill for the long term. Compliance violations and fines can damage the confidence of stakeholders and even impact board tenure. Gartner notes that organizations need to create their own value chain, looking at the continuum of security/risk dependencies, IT dependencies, business process and business outcomes and determining the causal relationships connected to each dependency. The message is, reporting tied to business value needs this level of analysis to support board evaluation of risk and to determine risk tolerance.
In parallel, the cyber security industry is now working with regulators and businesses alike to develop the concept of a set of formal statements around cyber resilience to provide evidence of best practices and proportionality, backed up by standards, technical assessments, maturity models and a number of other relevant metrics. These documents will then be signed off by suitably credentialed professionals from within the cyber security industry and combined to provide an overall opinion on the company’s cyber security resilience.
By more extensive risk reporting and analysis and standardizing on cyber resilience criteria within the security industry, boardrooms will be able to make better informed assessments of their company’s risk posture and plan more carefully for investments for a more secure future.
What are your thoughts on the topic?
If your organization runs an OWA server exposed to the internet, assume compromise between 02/26-03/03. Check for 8 character aspx files in C:\\inetpub\wwwroot\aspnet_client\system_web\. If you get a hit on that search, you’re now in incident response mode.
Microsoft has detected multiple 0-day exploits being used to attack on-premises versions of Microsoft Exchange Server in limited and targeted attacks. In the attacks observed, the threat actor used these vulnerabilities to access on-premises Exchange servers which enabled access to email accounts, and allowed installation of additional malware to facilitate long-term access to victim environments. Microsoft Threat Intelligence Center (MSTIC) attributes this campaign with high confidence to HAFNIUM, a group assessed to be state-sponsored and operating out of China, based on observed victimology, tactics and procedures.
The vulnerabilities recently being exploited were CVE-2021-26855, CVE-2021-26857, CVE-2021-26858, and CVE-2021-27065, all of which were addressed in today’s Microsoft Security Response Center (MSRC) release – Multiple Security Updates Released for Exchange Server. We strongly urge customers to update on-premises systems immediately. Exchange Online is not affected.
Update [03/04/2020]: The Exchange Server team released a script for checking HAFNIUM indicators of compromise (IOCs). See Scan Exchange log files for indicators of compromise.
We are sharing this information with our customers and the security community to emphasize the critical nature of these vulnerabilities and the importance of patching all affected systems immediately to protect against these exploits and prevent future abuse across the ecosystem. This blog also continues our mission to shine a light on malicious actors and elevate awareness of the sophisticated tactics and techniques used to target our customers. The related IOCs, Azure Sentinel advanced hunting queries, and Microsoft Defender for Endpoint product detections and queries shared in this blog will help SOCs proactively hunt for related activity in their environments and elevate any alerts for remediation.
Microsoft would like to thank our industry colleagues at Volexity and Dubex for reporting different parts of the attack chain and their collaboration in the investigation. Volexity has also published a blog post with their analysis. It is this level of proactive communication and intelligence sharing that allows the community to come together to get ahead of attacks before they spread and improve security for all.
Who is HAFNIUM?HAFNIUM primarily targets entities in the United States across a number of industry sectors, including infectious disease researchers, law firms, higher education institutions, defense contractors, policy think tanks, and NGOs.
HAFNIUM has previously compromised victims by exploiting vulnerabilities in internet-facing servers, and has used legitimate open-source frameworks, like Covenant, for command and control. Once they’ve gained access to a victim network, HAFNIUM typically exfiltrates data to file sharing sites like MEGA.
In campaigns unrelated to these vulnerabilities, Microsoft has observed HAFNIUM interacting with victim Office 365 tenants. While they are often unsuccessful in compromising customer accounts, this reconnaissance activity helps the adversary identify more details about their targets’ environments.
HAFNIUM operates primarily from leased virtual private servers (VPS) in the United States.
Technical detailsMicrosoft is providing the following details to help our customers understand the techniques used by HAFNIUM to exploit these vulnerabilities and enable more effective defense against any future attacks against unpatched systems.
CVE-2021-26855 is a server-side request forgery (SSRF) vulnerability in Exchange which allowed the attacker to send arbitrary HTTP requests and authenticate as the Exchange server.
CVE-2021-26857 is an insecure deserialization vulnerability in the Unified Messaging service. Insecure deserialization is where untrusted user-controllable data is deserialized by a program. Exploiting this vulnerability gave HAFNIUM the ability to run code as SYSTEM on the Exchange server. This requires administrator permission or another vulnerability to exploit.
CVE-2021-26858 is a post-authentication arbitrary file write vulnerability in Exchange. If HAFNIUM could authenticate with the Exchange server then they could use this vulnerability to write a file to any path on the server. They could authenticate by exploiting the CVE-2021-26855 SSRF vulnerability or by compromising a legitimate admin’s credentials.
CVE-2021-27065 is a post-authentication arbitrary file write vulnerability in Exchange. If HAFNIUM could authenticate with the Exchange server then they could use this vulnerability to write a file to any path on the server. They could authenticate by exploiting the CVE-2021-26855 SSRF vulnerability or by compromising a legitimate admin’s credentials.
Attack detailsAfter exploiting these vulnerabilities to gain initial access, HAFNIUM operators deployed web shells on the compromised server. Web shells potentially allow attackers to steal data and perform additional malicious actions that lead to further compromise. One example of a web shell deployed by HAFNIUM, written in ASP, is below:
Following web shell deployment, HAFNIUM operators performed the following post-exploitation activity:
HAFNIUM operators were also able to download the Exchange offline address book from compromised systems, which contains information about an organization and its users.
Our blog, Defending Exchange servers under attack, offers advice for improving defenses against Exchange server compromise. Customers can also find additional guidance about web shell attacks in our blog Web shell attacks continue to rise.
Can I determine if I have been compromised by this activity?The below sections provide indicators of compromise (IOCs), detection guidance, and advanced hunting queries to help customers investigate this activity using Exchange server logs, Azure Sentinel, Microsoft Defender for Endpoint, and Microsoft 365 Defender. We encourage our customers to conduct investigations and implement proactive detections to identify possible prior campaigns and prevent future campaigns that may target their systems.
Check patch levels of Exchange ServerThe Microsoft Exchange Server team has published a blog post on these new Security Updates providing a script to get a quick inventory of the patch-level status of on-premises Exchange servers and answer some basic questions around installation of these patches.
Scan Exchange log files for indicators of compromiseThe Exchange Server team has created a script to run a check for HAFNIUM IOCs to address performance and memory concerns. That script is available here: https://github.com/microsoft/CSS-Exchange/tree/main/Security.
Host IOCsHashesWeb shell hashes
Customers should monitor these paths for LSASS dumps:
Microsoft Defender Antivirus detectionsPlease note that some of these detections are generic detections and not unique to this campaign or these exploits.
Microsoft Defender for Endpoint advanced hunting queriesMicrosoft 365 Defender customers can find related hunting queries below or at this GitHub location: https://github.com/microsoft/Microsoft-365-Defender-Hunting-Queries/
Additional queries and information are available via Threat Analytics portal for Microsoft Defender customers.
UMWorkerProcess.exe in Exchange creating abnormal content
Look for Microsoft Exchange Server’s Unified Messaging service creating non-standard content on disk, which could indicate web shells or other malicious content, suggesting exploitation of CVE-2021-26858 vulnerability:
DeviceFileEvents | where InitiatingProcessFileName == "UMWorkerProcess.exe" | where FileName != "CacheCleanup.bin" | where FileName !endswith ".txt" | where FileName !endswith ".LOG" | where FileName !endswith ".cfg" | where FileName != "cleanup.bin"
Look for Microsoft Exchange Server’s Unified Messaging service spawning abnormal subprocesses, suggesting exploitation of CVE-2021-26857 vulnerability:
DeviceProcessEvents | where InitiatingProcessFileName == "UMWorkerProcess.exe" | where FileName != "wermgr.exe" | where FileName != "WerFault.exe"
Please note excessive spawning of wermgr.exe and WerFault.exe could be an indicator of compromise due to the service crashing during deserialization.
Azure Sentinel advanced hunting queriesAzure Sentinel customers can find a Sentinel query containing these indicators in the Azure Sentinel Portal or at this GitHub location: https://github.com/Azure/Azure-Sentinel/tree/master/Detections/MultipleDataSources/.
Look for Nishang Invoke-PowerShellTcpOneLine in Windows Event Logging:
SecurityEvent | where EventID == 4688 | where Process has_any ("powershell.exe", "PowerShell_ISE.exe") | where CommandLine has "$client = New-Object System.Net.Sockets.TCPClient"
Look for downloads of PowerCat in cmd and Powershell command line logging in Windows Event Logs:
SecurityEvent | where EventID == 4688 | where Process has_any ("cmd.exe", "powershell.exe", "PowerShell_ISE.exe") | where CommandLine has "https://raw.githubusercontent.com/besimorhino/powercat/master/powercat.ps1"
Look for Exchange PowerShell Snapin being loaded. This can be used to export mailbox data, subsequent command lines should be inspected to verify usage:
SecurityEvent | where EventID == 4688 | where Process has_any ("cmd.exe", "powershell.exe", "PowerShell_ISE.exe") | where isnotempty(CommandLine) | where CommandLine contains "Add-PSSnapin Microsoft.Exchange.Powershell.Snapin" | summarize FirstSeen = min(TimeGenerated), LastSeen = max(TimeGenerated) by Computer, Account, CommandLine
Watch the webinar for an introduction and overview of the US Cybersecurity Maturity Model Certification (CMMC). Key CMMC stakeholders share the practical steps that an organization can take in order to prepare for CMMC requirements; discuss market opportunities resulting from CMMC; and explain the role of tools in conducting CMMC assessments.
The Panel: Karlton Johnson – Vice Chairman, Board Directors of CMMC
Katie Arrington – CISO, A&S Organization, Department of Defense
Charlie Tupitza – Cybersecurity & Data Breach Protection Lead,SBA
Tony Sager – Senior Vice President, Center for Internet Security
Phil Lewis, COO – Titania
Armando Seay – Director, Maryland Innovation and Security Institute (MISI)
Moderator: Tom Brennan, Chair – CREST USA Chairman / ProactiveRISK
** Updated 11/10
Additional information can be found in the DFARS summary