North Korea-linked Dark Hotel APT leverages CVE-2018
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2018-8174 | Out-of-Bounds Write RCE in Microsoft Windows VBScript Engine CVE-2018-8174 is an out-of-bounds write (CWE-787) in the Microsoft Windows VBScript engine, caused by the way it handles objects in memory. An attacker triggers it by convincing a user to visit a specially crafted website or open crafted content that invokes the VBScript engine (for example via Internet Explorer or a document preview), requiring user interaction. Successful exploitation yields remote code execution with the privileges of the logged-on user, enabling program installation, data theft and account takeover. All listed Windows client and server releases are affected: Windows 7, 8.1, RT 8.1, Windows 10 (1607-1803), and Windows Server 2008/2008 R2, 2012/2012 R2, 2016. Exploitation is in the wild: the flaw was fixed in the May 2018 Patch Tuesday, is listed in CISA KEV with known ransomware use, and public PoCs (0patch, ExploitDB 44741) and exploit kit usage have been documented; EPSS puts its 30-day exploitation probability at 88.5%. Do: Apply Microsoft's May 2018 security updates (and any later cumulative or Extended Security Updates) to every listed Windows client and server release, as required by the CISA KEV listing, prioritizing internet-reachable and user-facing systems given known ransomware use. Upgrade out-of-support platforms (Windows 7/8.1/RT 8.1, Server 2008/2008 R2, 2012/2012 R2) to supported builds or ensure ESU coverage. As interim mitigation, block VBScript execution in Internet Explorer web zones using Microsoft's documented Group Policy/registry settings, and hunt for prior exploitation on legacy systems. | 7.5 | 88% | KEV ransomware PoC ×2 |
| masshundreds of millions of Windows PCs and servers (affected desktop releases dominated the ~1B+ device Windows install base at disclosure) | |
| CVE-2018-8373 | Memory Corruption RCE in Microsoft Internet Explorer Scripting Engine CVE-2018-8373 is an out-of-bounds write (CWE-787) in the Microsoft scripting engine's handling of objects in memory, which can corrupt memory and enable remote code execution in Internet Explorer 9, 10, and 11. It is triggered when a user is lured to an attacker-crafted web page or script in IE, with no privileges required but user interaction and relatively high attack complexity per the CVSS vector (AV:N/AC:H/UI:R). A successful attacker gains arbitrary code execution in the context of the current user, compromising that workstation's data and credentials. Any Windows system whose users browse with Internet Explorer 9, 10, or 11 was affected, and Microsoft fixed the flaw in its August 2018 Patch Tuesday release. The flaw was exploited as a zero-day in the wild at the time of patching — press coverage describes an in-the-wild VBScript zero-day blocked by endpoint protection — and it was added to CISA's Known Exploited Vulnerabilities catalog on 2022-03-25; EPSS places the 30-day exploitation probability at 61.9% (99th percentile). Do: Apply Microsoft's August 2018 security updates for Internet Explorer on all supported Windows versions — the required action listed in the CISA KEV — and verify patch deployment via WSUS/SCCM/Intune across end-user workstations and RDS/browsing hosts. As interim mitigation, consider Microsoft's documented workaround of disabling VBScript execution in IE via feature-control keys and steer users away from IE for web browsing. Finally, migrate any remaining IE9/10/11 usage to Microsoft Edge (using IE mode for legacy sites), since IE11 is retired and this flaw is confirmed exploited in the wild. | 7.5 | 62% | KEV |
| masshundreds of millions of Windows devices (IE9–11 shipped with Windows; IE11 present by default on Windows 7/8.1/10) |
Indicators of compromiseauto-extracted · verify before use · export allAll →
| Type | Indicator | Context |
|---|---|---|
| domain | ov.php | t given by Trend Micro (http ://windows-updater[.]net/stack/ov[.]php?w= 1\x00who =1)” In the analysis published in May by Qiho |
| domain | windows-updater.net | ro coding through the big data analysis association: http://windows-updater[.]net/realmuto/wood[.]php?who=1?????? Associated homologous 0da |
| domain | wood.php | analysis association: http://windows-updater[.]net/realmuto/wood[.]php?who=1?????? Associated homologous 0day attack sample” sta |
Full article554 words · extracted from securityaffairs.com · click to collapse
The North Korea-linked Dark Hotel APT group is leveraging the recently patched CVE-2018-8373 vulnerability in the VBScript engine in attacks in the wild.
The vulnerability affects Internet Explorer 9, 10 and 11, it was first disclosed last month by Trend Micro and affected all supported versions of Windows.
The flaw could be exploited by remote attackers to take control of the vulnerable systems by tricking victims into viewing a specially crafted website through Internet Explorer. The attacker could also embed an ActiveX control marked ‘safe for initialization’ in an application or Microsoft Office document that hosts the IE rendering engine.
“A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user.” reads the security advisory published by Microsoft.
“An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.”
The analysis of the exploit code for the CVE-2018-8373 revealed it shared the obfuscation technique implemented for another exploit triggering the CVE-2018-8174 flaw.
The CVE-2018-8174 was first discovered by experts at Chinese security company Qihoo 360 and it was fixed in May by Microsoft.
The similarities in the exploits suggest that were developed by the same threat actor.
“We found this exploit using heuristics, which led to a more in-depth analysis. Interestingly, we found that this exploit sample uses the same obfuscation technique as exploits for CVE-2018-8174, a VBScript engine remote code execution vulnerability patched back in May” wrote Trend Micro.
“We suspect that this exploit sample came from the same creator. Our analysis revealed that it used a new use-after-free (UAF) vulnerability in vbscript.dll, which remained unpatched in the latest VBScript engine.”
A similar theory was proposed by experts from Qihoo that collected evidence that linked the use of the CVE-2018-8373 exploit to Dark Hotel.
The experts discovered that domain name embedded in Office documents in latest attacks is the same used to download Double Kill exploit code in previous attacks linked to the North Korea-linked APT group.
“The 360 Threat Intelligence Center first obtained the IOC address after Trend Micro coding through the big data analysis association:
http://windows-updater[.]net/realmuto/wood[.]php?who=1??????
Associated homologous 0day attack sample” states Qihoo
“And found an attack time and trend technology found in the wild “double kill” 0day attack on the same day suspected of using the 0day attack of the office document sample, the domain name embedded in the Offce document sample and the domain name format given by Trend Micro (http ://windows-updater[.]net/stack/ov[.]php?w= 1\x00who =1)”
In the analysis published in May by Qihoo 360 the researchers associated the CVE-2018-8373 exploit with Dark Hotel based on TTPs associated with the threat actor (e.g. the decryption algorithm that malware used is identical to Dark Hotel’s one).
Experts speculated that the CVE-2018-8373 was used in a cyber espionage campaign aimed at China.
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(Security Affairs – Dark Hotel, APT)
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Text extracted automatically; images, tables and formatting may be missing. Original: https://securityaffairs.com/75459/hacking/cve-2018-8373-dark-hotel.html