North Korea Hackers Using New "Dolphin" Backdoor to Spy on South Korean Targets
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2020-1380 | Memory Corruption RCE in Microsoft Internet Explorer Scripting Engine CVE-2020-1380 is a memory corruption vulnerability (an out-of-bounds write, CWE-787) in the Microsoft Internet Explorer scripting engine that can corrupt memory when the engine processes maliciously crafted script content. It is triggered by luring a user to visit an attacker-controlled or compromised web page in Internet Explorer or in an application that invokes the IE engine, with no authentication required. Successful exploitation allows the attacker to execute arbitrary code in the context of the current user, gaining that user's privileges on the system. All installations of the affected Microsoft Internet Explorer versions are potentially exposed, with the greatest risk to legacy and enterprise Windows systems that still browse or render content with IE. The flaw is on CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating exploitation in the wild, while no public proof-of-concept is known and ransomware use is unconfirmed. Do: Apply Microsoft's June 2020 (or later) Windows cumulative security updates on every system running Internet Explorer, per the vendor instructions cited by CISA. Given the KEV listing (added 2021-11-03) and high EPSS (~24% 30-day exploitation probability, 98th percentile), treat this as a priority patch. Reduce attack surface by steering users to Microsoft Edge instead of IE for web browsing and auditing internal apps or legacy sites that still invoke the IE engine to render external content. | 7.8 | 24% | KEV |
| masshundreds of millions of Windows devices historically able to run Internet Explorer; exact currently-vulnerable count unknown | |
| CVE-2021-26411 | Use-After-Free Memory Corruption in Microsoft Internet Explorer Exploited in the Wild CVE-2021-26411 is a use-after-free (CWE-416) memory corruption vulnerability in Microsoft Internet Explorer's web rendering engine that can lead to remote code execution. It is triggered when a user, typically lured via a link, email, or watering-hole page, views attacker-controlled web content that corrupts memory, consistent with the CVSS profile requiring network access and user interaction. A successful attacker gains code execution in the context of the logged-on user, which in observed campaigns was chained into malware delivery (including exploit-kit payloads such as Dridex and VBA-based malware). Any Windows system that renders web content with Internet Explorer or its IE/MSHTML components (Edge is also listed among affected CPE products) is potentially affected, though specific version ranges are not provided in the source data. The flaw was exploited as a zero-day around Microsoft's March 2021 Patch Tuesday, was added to CISA KEV on 2021-11-03 with known ransomware use, and carries an 80.8% EPSS probability of exploitation within 30 days. Do: Apply Microsoft's March 2021 cumulative security updates for Internet Explorer, or any later cumulative update, across all Windows clients and servers, prioritizing user workstations per the CISA KEV required action. Review proxy and endpoint logs for visits to compromised watering-hole sites (notably Korean-language news sites) and for follow-on malware such as Dridex, and restrict or disable IE/legacy IE-mode rendering of untrusted web content where feasible. | 8.8 | 81% | KEV ransomware |
| mass≈hundreds of millions of Windows endpoints (IE/MSHTML components are present on effectively all supported Windows clients and servers) |
Full article461 words · extracted from thehackernews.com · click to collapse
Ravie LakshmananNov 30, 2022
The North Korea-linked ScarCruft group has been attributed to a previously undocumented backdoor called Dolphin that the threat actor has used against targets located in its southern counterpart.
"The backdoor [...] has a wide range of spying capabilities, including monitoring drives and portable devices and exfiltrating files of interest, keylogging and taking screenshots, and stealing credentials from browsers," ESET researcher Filip Jurčacko said in a new report published today.
Dolphin is said to be selectively deployed, with the malware using cloud services like Google Drive for data exfiltration as well as command-and-control.
The Slovak cybersecurity company said it found the implant deployed as a final-stage payload as part of a watering hole attack in early 2021 directed against a South Korean digital newspaper.
The campaign, first uncovered by Kaspersky and Volexity last year, entailed the weaponization of two Internet Explorer flaws (CVE-2020-1380 and CVE-2021-26411) to drop a backdoor named BLUELIGHT.
ScarCruft, also called APT37, InkySquid, Reaper, and Ricochet Chollima, is a geo-political motivated APT group that has a track record of attacking government entities, diplomats, and news organizations associated with North Korean affairs. It's been known to be active since at least 2012.
Earlier this April, cybersecurity firm Stairwell disclosed details of a spear-phishing attack targeting journalists covering the country with the ultimate goal of deploying a malware dubbed GOLDBACKDOOR that shares tactical overlaps with BLUELIGHT.
The latest findings from ESET shed light on a second, more sophisticated backdoor delivered to a small pool of victims via BLUELIGHT, indicative of a highly-targeted espionage operation.
This, in turn, is achieved by executing an installer shellcode that activates a loader comprising a Python and shellcode component, the latter of which runs another shellcode loader to drop the backdoor.
"While the BLUELIGHT backdoor performs basic reconnaissance and evaluation of the compromised machine after exploitation, Dolphin is more sophisticated and manually deployed only against selected victims," Jurčacko explained.
What makes Dolphin a lot more potent than BLUELIGHT is its ability to search removable devices and connected smartphones, and exfiltrate files of interest, such as media, documents, emails, and certificates.
The backdoor, since its original discovery in April 2021, is said to have undergone three successive iterations that come with its own set of feature improvements and grant it more detection evasion capabilities.
"Dolphin is another addition to ScarCruft's extensive arsenal of backdoors abusing cloud storage services," Jurčacko said. "One unusual capability found in prior versions of the backdoor is the ability to modify the settings of victims' Google and Gmail accounts to lower their security, presumably in order to maintain account access for the threat actors."
Found this article interesting? Follow us on Google News, Twitter and LinkedIn to read more exclusive content we post.
Text extracted automatically; images, tables and formatting may be missing. Original: https://thehackernews.com/2022/12/north-korea-hackers-using-new-dolphin.html