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Oct 18, 2021
Grief Ransomware Gang Claims 41 New Victims, Targeting Manufacturers; Municipalities; & Service Companies in U.K. & Europe
Grief Operators Earned an Estimated 8.5 Million British Pounds in Four Months Key Findings: The Grief Ransomware Gang (a rebrand of the DoppelPaymer Ransomware Group) claims to have infected 41 new victims between May 27, 2021—Oct. 1, 2021 with their ransomware.Over half the companies listed on Grief’s underground leak site are based in the U.K. and Europe. The Grief Ransomware Gang appears to…
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eSentire Launches MDR with Microsoft Azure Sentinel Extending Response Capabilities Across Entire Microsoft Security Ecosystem
Waterloo, ON – Oct. 12, 2021 -- eSentire, recognized globally as the Authority in Managed Detection and Response (MDR), today announced the expansion of its award-winning MDR services with Microsoft Azure Sentinel, as part of its integration with the complete Microsoft 365 Defender and Azure Defender product suites supporting Microsoft SIEM, endpoint, identity, email and cloud security services.…
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Security advisories — Feb 27, 2019

Microsoft Exchange Server Elevation of Privilege Vulnerability

A new attack technique has been identified by security researcher Dirk-jan Mollema, which could allow an attacker to impersonate other Exchange users and elevate privileges [1].

Microsoft has released updated guidance on this issue which includes security updates to Exchange [2].

Proof-of-concept (PoC) code is available and is simple to use [3]. Customers are advised to test and deploy available security updates as soon as possible.

What we’re doing about it

What you should do about it

Additional information

The attack is conducted by using the Exchange Web Services' PushSubscription service to subscribe for push events, pointing them to the attacker’s machine. Exchange will connect to the attacker’s machine using the PushSubscriptionRequest method where it will attempt to authenticate using NTLM credentials (for the computer account of the Exchange server). These credentials are then relayed to a Domain Controller where the Exchange account can be used to elevate privileges for an account under the attacker’s control.

Unpatched Exchange 2013, 2016 and 2019 have been confirmed as vulnerable to this attack.

References:

[1] https://dirkjanm.io/abusing-exchange-one-api-call-away-from-domain-admin/

[2] https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0686

[3] https://github.com/dirkjanm/PrivExchange

[4] https://blogs.technet.microsoft.com/exchange/2019/02/12/released-february-2019-quarterly-exchange-updates/