The Hacker Newspublished Jan 8, 04:12 UTC (Jan 8, 2024)ingested Sep 10, 05:53 UTC@TheHackersNews

CERT-UA Uncovers New Malware Wave Distributing OCEANMAP, MASEPIE, STEELHOOK

criticalMalwareimportance 60CVE-2023-23397

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Vulnerabilities mentionedAll →

CVE	Vulnerability	CVSS	EPSS	Flags	Affected	Exposure	Published
CVE-2023-23397	Zero-Click Elevation of Privilege in Microsoft Outlook (Forced NTLM Credential Leak) CVE-2023-23397 is an elevation of privilege vulnerability in Microsoft Outlook caused by improper input validation (CWE-20) combined with authentication bypass via spoofed authentication data on the channel (CWE-294), allowing an attacker to force Outlook to authenticate to an attacker-controlled SMB/WebDAV server. It is triggered when Outlook processes a crafted email or calendar object — for example a meeting or task reminder whose sound property points to an attacker-supplied UNC path — and requires no user interaction. That authentication exchange leaks the victim's NTLM credential hash, which the attacker can crack offline or relay to authenticate as the victim and access resources such as Exchange mailboxes, effectively escalating privileges. Affected software spans Microsoft 365 Apps, Microsoft Office (including the Long Term Servicing Channel), and Microsoft Outlook, which are deployed across enterprises, governments, and militaries worldwide. It is actively exploited in the wild — added to CISA's Known Exploited Vulnerabilities catalog on 2023-03-14 with a 97.4% EPSS — and Microsoft has warned of exploitation by Russia-aligned threat actors in campaigns against government and military mail servers, with patches shipped in Microsoft's March 2023 security updates. Do: Apply Microsoft's March 2023 security updates to Microsoft 365 Apps, Office/LTSC, and Outlook immediately, per CISA's required action. As interim mitigation, enable Extended Protection for Authentication or add accounts to the Protected Users group to block the NTLM credential leak, and audit calendar and task reminder sound properties for UNC paths (Microsoft published an audit/cleanup script for this) while watching for unexpected outbound SMB/WebDAV connections from hosts running Outlook.	9.8	97%	KEV	Microsoft 365 Apps Affected builds as covered by Microsoft's March 2023 security updates; see Microsoft advisory for exact build ranges Microsoft Office Affected builds as covered by Microsoft's March 2023 security updates; see Microsoft advisory for exact build ranges Microsoft Office Long Term Servicing Channel (LTSC) Affected builds as covered by Microsoft's March 2023 security updates; see Microsoft advisory for exact build ranges +1 more	masson the order of hundreds of millions of users (Outlook ships with Microsoft Office/Microsoft 365, the dominant enterprise and government email suite)	Mar 14, 2023

CVE

Vulnerability

CVSS

EPSS

Flags

Affected

Exposure

Published

CVE-2023-23397

Zero-Click Elevation of Privilege in Microsoft Outlook (Forced NTLM Credential Leak)

CVE-2023-23397 is an elevation of privilege vulnerability in Microsoft Outlook caused by improper input validation (CWE-20) combined with authentication bypass via spoofed authentication data on the channel (CWE-294), allowing an attacker to force Outlook to authenticate to an attacker-controlled SMB/WebDAV server. It is triggered when Outlook processes a crafted email or calendar object — for example a meeting or task reminder whose sound property points to an attacker-supplied UNC path — and requires no user interaction. That authentication exchange leaks the victim's NTLM credential hash, which the attacker can crack offline or relay to authenticate as the victim and access resources such as Exchange mailboxes, effectively escalating privileges. Affected software spans Microsoft 365 Apps, Microsoft Office (including the Long Term Servicing Channel), and Microsoft Outlook, which are deployed across enterprises, governments, and militaries worldwide. It is actively exploited in the wild — added to CISA's Known Exploited Vulnerabilities catalog on 2023-03-14 with a 97.4% EPSS — and Microsoft has warned of exploitation by Russia-aligned threat actors in campaigns against government and military mail servers, with patches shipped in Microsoft's March 2023 security updates.

Do: Apply Microsoft's March 2023 security updates to Microsoft 365 Apps, Office/LTSC, and Outlook immediately, per CISA's required action. As interim mitigation, enable Extended Protection for Authentication or add accounts to the Protected Users group to block the NTLM credential leak, and audit calendar and task reminder sound properties for UNC paths (Microsoft published an audit/cleanup script for this) while watching for unexpected outbound SMB/WebDAV connections from hosts running Outlook.

9.8

97%

KEV

Microsoft 365 Apps Affected builds as covered by Microsoft's March 2023 security updates; see Microsoft advisory for exact build ranges
Microsoft Office Affected builds as covered by Microsoft's March 2023 security updates; see Microsoft advisory for exact build ranges
Microsoft Office Long Term Servicing Channel (LTSC) Affected builds as covered by Microsoft's March 2023 security updates; see Microsoft advisory for exact build ranges
+1 more

masson the order of hundreds of millions of users (Outlook ships with Microsoft Office/Microsoft 365, the dominant enterprise and government email suite)

Mar 14, 2023

Full article396 words · extracted from thehackernews.com · click to collapse

Ravie LakshmananDec 29, 2023Email Security / Malware

The Computer Emergency Response Team of Ukraine (CERT-UA) has warned of a new phishing campaign orchestrated by the Russia-linked APT28 group to deploy previously undocumented malware such as OCEANMAP, MASEPIE, and STEELHOOK to harvest sensitive information.

The activity, which was detected by the agency between December 15 and 25, 2023, targeted Ukrainian government entities and Polish organizations with email messages urging recipients to click on a link to view a document.

However, to the contrary, the links redirect to malicious web resources that abuse JavaScript and the "search-ms:" URI protocol handler to drop a Windows shortcut file (LNK) that launches PowerShell commands to activate an infection chain for a new malware known as MASEPIE.

MASEPIE is a Python-based tool to download/upload files and execute commands, with communications with the command-and-control (C2) server taking place over an encrypted channel using the TCP protocol.

The attacks further pave the way for the deployment of additional malware, including a PowerShell script called STEELHOOK that's capable of harvesting web browser data and exporting it to an actor-controlled server in Base64-encoded format.

Also delivered is a C#-based backdoor dubbed OCEANMAP that's designed to execute commands using cmd.exe.

"The IMAP protocol is used as a control channel," CERT-UA said, adding persistence is achieved by creating a URL file named "VMSearch.url" in the Windows Startup folder.

"Commands, in Base64-encoded form, are contained in the 'Drafts' of the corresponding email directories; each of the drafts contains the name of the computer, the name of the user and the version of the OS. The results of the commands are stored in the inbox directory."

The agency further pointed out that reconnaissance and lateral movement activities are carried out within an hour of the initial compromise by taking advantage of tools like Impacket and SMBExec.

The disclosure comes weeks after IBM X-Force revealed APT28's use of lures related to the ongoing Israel-Hamas war to facilitate the delivery of a custom backdoor called HeadLace.

In recent weeks, the prolific Kremlin-backed hacking group has also been attributed to the exploitation of a now-patched critical security flaw in the Microsoft Outlook email service (CVE-2023-23397, CVSS score: 9.8) to gain unauthorized access to victims' accounts within Exchange servers.

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Text extracted automatically; images, tables and formatting may be missing. Original: https://thehackernews.com/2023/12/cert-ua-uncovers-new-malware-wave.html