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Sep 23, 2021
SolarMarker Malware Activity
THE THREAT eSentire has observed a recent and significant increase in SolarMarker infections delivered through drive-by download attacks. These attacks rely on social engineering techniques to persuade users to execute malware disguised as document templates. SolarMarker is a modular information-stealing malware; infections may result in the theft of sensitive data including user credentials.…
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eSentire is The Authority in Managed Detection and Response Services, protecting the critical data and applications of 1000+ organizations in 70+ countries from known and unknown cyber threats. Founded in 2001, the company’s mission is to hunt, investigate and stop cyber threats before they become business disrupting events.
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Aug 25, 2021
eSentire named a Leader in IDC MarketScape for U.S. Managed Detection and Response Services
August 26, 2021 – Waterloo, ON -  eSentire, recognized globally as the Authority in Managed Detection and Response (MDR), announced today that it has been named a Leader in the IDC MarketScape: U.S. Managed Detection and Response Services 2021 Vendor Assessment (doc #US48129921, August 2021). IDC defines the core services an MDR must provide as follows: reduced time for onboarding, 24/7…
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Security advisories — Sep 13, 2021

Microsoft Zero-Day Vulnerability Announced - CVE-2021-40444

THE THREAT

UPDATE: As of September 11th, public Proof-of-Concept (PoC) exploit code has been released for CVE-2021-40444. The availability of PoC code is expected to result in widespread exploitation of this vulnerability in the near future. eSentire security teams will continue to review exploit and malware samples for additional detection and prevention opportunities.

On September 7th, 2021, Microsoft announced a new critical zero-day vulnerability impacting Windows devices. The vulnerability, tracked as CVE-2021-40444 (CVSS: 8.8), is an unauthenticated Remote Code Execution vulnerability. In an attack scenario, an adversary would send a maliciously crafted document to the potential victim; if the document is opened, code execution is achieved.

Microsoft has confirmed that targeted exploitation is ongoing. It is recommended that organizations apply the mitigations provided by Microsoft until security patches are released.

What we’re doing about it

What you should do about it

Additional information

External security researchers have identified potential bypasses to the mitigations provided by Microsoft. As such, it is highly recommended that organizations apply the relevant security patches once released. Microsoft has not stated when security patches will be made available. Microsoft claims that both Microsoft Defender Antivirus and Defender for Endpoint can detect the exploitation of this vulnerability. It should be noted that user interaction is required for successful exploitation of this vulnerability. As such, users should be informed of the risks of opening unexpected documents and emails.

CVE-2021-40444 is a vulnerability found in MSHTML, the file that allows Microsoft Internet Explorer to read and display HTML webpages.

At this point, attacks exploiting CVE-2021-40444 are believed to be targeted in nature, likely by a single threat actor group. The publication of the vulnerability’s details is likely to lead to wider exploitation in the immediate future.

Impacted Products:

References:

[1] https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-40444
[2] https://twitter.com/GossiTheDog/status/1435570418623070210