ZeroHour
Cisco Talospublished ()ingested

We all just need to agree that ad blockers are good

Vulnerabilities mentionedAll →

CVEVulnerabilityCVSSEPSSFlagsAffectedExposurePublished
CVE-2023-20592
Improper or unexpected behavior of the INVD instruction in some AMD CPUs may allow an attacker with a malicious hypervisor to affect cache line write-back behav

Improper or unexpected behavior of the INVD instruction in some AMD CPUs may allow an attacker with a malicious hypervisor to affect cache line write-back behavior of the CPU leading to a potential loss of guest virtual machine (VM) memory integrity.

NVD description · AI analysis pending
6.51%
  • amd epyc 7001 firmware
  • amd epyc 7251 firmware
  • amd epyc 7261 firmware
  • +1 more
CVE-2023-23583
Sequence of processor instructions leads to unexpected behavior for some Intel(R) Processors may allow an authenticated user to potentially enable escalation of

Sequence of processor instructions leads to unexpected behavior for some Intel(R) Processors may allow an authenticated user to potentially enable escalation of privilege and/or information disclosure and/or denial of service via local access.

NVD description · AI analysis pending
7.82%
  • intel core i3-10100y firmware
  • intel core i3-10110u firmware
  • intel core i3-10110y firmware
  • +1 more
CVE-2023-36036
+1 in the same advisory: …36033
Local Privilege Escalation in Microsoft Windows Cloud Files Mini Filter Driver

CVE-2023-36036 is a high-severity (CVSS 7.8) elevation-of-privilege flaw caused by an out-of-bounds/heap-based buffer overflow write (CWE-122, CWE-787) in the Windows Cloud Files Mini Filter Driver, the kernel component that manages cloud-synced placeholder files (e.g., cloud storage 'files on demand' such as OneDrive). A local attacker who can already run low-privileged code on a vulnerable machine can trigger the flaw with no user interaction and escalate to SYSTEM/administrator-level privileges, enabling full control of the host and potential chaining with other vulnerabilities. The affected scope spans Windows 10 (1507, 1607, 1809, 21H2, 22H2), Windows 11 (21H2, 22H2, 23H2), and Windows Server 2008, 2012, 2016, and 2019, meaning the driver is present by default across essentially the entire Windows install base until patched. The vulnerability is confirmed exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2023-11-14, and it was among the three actively exploited flaws fixed in Microsoft's November 2023 Patch Tuesday; ransomware use is unknown. No public proof-of-concept is catalogued, but the EPSS probability of 16.7% (97th percentile) and the KEV listing make this a patching priority.

Do: Apply the Microsoft November 2023 Patch Tuesday security updates (released 2023-11-14) to every in-scope Windows 10, Windows 11, and Windows Server host, prioritizing endpoints where untrusted or low-privileged users can execute code, and verify installation via Windows Update history or patch-management reporting. Per CISA's KEV required action, apply vendor mitigations or discontinue use of unpatched versions; no standalone workaround or public PoC is catalogued, so patching is the primary remediation. Because the flaw requires local access, focus early deployment on shared workstations, RDS/VDI hosts, and servers that expose interactive logon to non-administrative users.

7.817% KEV
  • microsoft Windows 10 1507, 1607, 1809, 21H2, 22H2
  • microsoft Windows 11 21H2, 22H2, 23H2
  • microsoft Windows Server 2008, 2012, 2016, 2019
masshundreds of millions of Windows 10/11 and Windows Server installations (order 10^8-10^9)

Indicators of compromiseAll →

TypeIndicatorContext
md5200206279107f4a2bb1832e3fcd7d64c8a912d4322b45ea64d69bb3add4d818fd1eb7723260b11d76a138a MD5: 200206279107f4a2bb1832e3fcd7d64c Typical Filename: lsgkozfm.bat Claimed Product: N/A Detecti
md53b100bdcd61bb1da816cd7eaf9ef13baec61e6b022a275d66312b5b676f9a0a9537a7708de9aa8ce34de59 MD5: 3b100bdcd61bb1da816cd7eaf9ef13ba Typical Filename: vt-upload-C6In1 Claimed Product: N/A Dete
md54c648967aeac81b18b53a3cb357120f4e2b891fa9c2dad1f63a9b26901d825dc6d6b9dcc6258a985f4f9ab MD5: 4c648967aeac81b18b53a3cb357120f4 Typical Filename: yypnexwqivdpvdeakbmmd.exe Claimed Product
md57bdbd180c081fa63ca94f9c22c45737683227f5e7988d1ad9c0aecd66d58bb7b4d8518ae23e110308dbf91 MD5: 7bdbd180c081fa63ca94f9c22c457376 Typical Filename: c0dwjdi6a.dll Claimed Product: N/A Detect
md5bbcf7a68f4164a9f5f5cb2d9f30d979039a5c39960ffa6b6b688faa7fc3075e130fe0d4599d5b95ef20647 MD5: bbcf7a68f4164a9f5f5cb2d9f30d9790 Typical Filename: bbcf7a68f4164a9f5f5cb2d9f30d9790.vir Clai
sha2560e2263d4f239a5c39960ffa6b6b688faa7fc3075e130fe0d4599d5b95ef20647ware files from Talos telemetry over the past week SHA 256: 0e2263d4f239a5c39960ffa6b6b688faa7fc3075e130fe0d4599d5b95ef20647 MD5: bbcf7a68f4164a9f5f5cb2d9f30d9790 Typical Filename: bbc
sha2561fa0222e5ae2b891fa9c2dad1f63a9b26901d825dc6d6b9dcc6258a985f4f9abd Product: N/A Detection Name: Backdoor:KillAV-tpd SHA 256: 1fa0222e5ae2b891fa9c2dad1f63a9b26901d825dc6d6b9dcc6258a985f4f9ab MD5: 4c648967aeac81b18b53a3cb357120f4 Typical Filename: yyp
sha256a31f222fc283227f5e7988d1ad9c0aecd66d58bb7b4d8518ae23e110308dbf91roduct: N/A Detection Name: Win.Dropper.Scar::1201 SHA 256: a31f222fc283227f5e7988d1ad9c0aecd66d58bb7b4d8518ae23e110308dbf91 MD5: 7bdbd180c081fa63ca94f9c22c457376 Typical Filename: c0d
sha256b9ddbd1a4cec61e6b022a275d66312b5b676f9a0a9537a7708de9aa8ce34de59roduct: N/A Detection Name: Win.Dropper.Scar::1201 SHA 256: b9ddbd1a4cec61e6b022a275d66312b5b676f9a0a9537a7708de9aa8ce34de59 MD5: 3b100bdcd61bb1da816cd7eaf9ef13ba Typical Filename: vt-
sha256bea312ccbc8a912d4322b45ea64d69bb3add4d818fd1eb7723260b11d76a138auct: N/A Detection Name: Trojan.GenericKD.33515991 SHA 256: bea312ccbc8a912d4322b45ea64d69bb3add4d818fd1eb7723260b11d76a138a MD5: 200206279107f4a2bb1832e3fcd7d64c Typical Filename: lsg
Full article1,492 words · extracted from blog.talosintelligence.com · click to collapse

Thursday, November 16, 2023 14:00

I don’t think this is a particularly bold take — but I’m not afraid to say that ad blockers are good! 

Ever since I started using one sometime in 2016, my experience of using the internet has improved exponentially. I can finally easily find a recipe for dinner on a random influencer’s blog, get a faster answer to “how to replace my car’s headlights” and likely avoid hundreds of pieces of malvertising

But their use has increasingly come into question with YouTube’s new policies on preventing users from using ad blockers on its site, with new warnings saying the user has a certain number of videos they can watch before they must allowlist youtube.com in their ad blocker, thus allowing the site to display ads before YouTube videos. 

The second this popped up for me two weeks ago, I immediately started researching workarounds and quickly found a secure solution that works for my browsing habits. The easy explanation for why Google (YouTube’s parent company) wants to get rid of ad blockers is, simply, money. They run the Google Ads service that provides the stereotypical ads everyone has been used to seeing on websites since the early aughts. Unfortunately, bad actors will often use enticing headlines, fake images or sales pitches to trick people into clicking on links that lead to malicious sites, attacker-run scams or downloads that are malware. 

Ad blockers are a major tool users can deploy to block this type of threat, so the explanation for why everyone should be using one is also clear. 

Google isn’t the only major company looking to bypass ad blockers, either. Spotify’s terms of service explicitly outlaws “circumventing or blocking advertisements or creating or distributing tools designed to block advertisements” on its platforms, and many news websites like CNBC have warnings about turning off your ad blocker before you can proceed to read an article. 

I am all for publishers charging for their content or putting it behind a paywall, or even “premium” subscriptions to disable ads from podcasts or videos. But we all need to universally agree that ad blockers (at least legitimate ones) are good for the internet at large and keep users safer. The FBI and CIA agree with me on this and have both advised that users enable ad blockers in web browsers before.

The argument that ads benefit the creators, and therefore we’re robbing them of money, is largely off-base from these corporations. 

Creators who are part of the YouTube Partner program, which means they have filled out an application and meet a minimum standard for views and subscribers, make between $1.61 and $29.30 for every 1,000 views on their videos through YouTube’s ads. So Mr. Beast might make a decent payday out of that every month, but I’m sure Mr. Beast would also be doing just fine without the extra few thousand dollars in his pocket currently. 

The people who are just trying to be helpful by showing me how to fix my washing machine or install a car seat properly are likely not missing my singular ad view when I use an ad blocker.  

Thankfully, YouTube’s new rules may not be around for long anyway, because they might run afoul of European Union regulations, and privacy advocates have already filed a formal challenge to the EU’s independent data regulator.  

The one big thing 

Microsoft disclosed three zero-day vulnerabilities as part of its monthly security update this week, and all three have already been added to CISA’s Known Exploited Vulnerabilities catalog. However, Patch Tuesday only included three critical vulnerabilities, an unusually small number based on previous months’ Patch Tuesdays. CVE-2023-36033 is an elevation of privilege vulnerability in the Windows DWM Core Library that could allow an attacker to gain SYSTEM-level privileges. According to Microsoft, this vulnerability has already been exploited in the wild and there is proof-of-concept code available. Another zero-day elevation of privilege vulnerability, CVE-2023-36036, exists in the Windows Cloud Files mini-filter driver that could also allow an attacker to gain SYSTEM privileges. 

Why do I care? 

Unfortunately, zero-days have become commonplace for Patch Tuesdays this year, and it seems like a few more pop up each month. In these cases, attackers were able to discover the exploits before Microsoft had a chance to patch them, and CISA already acknowledged that attackers are exploiting these vulnerabilities in the wild.  

So now what? 

All Microsoft users should ensure their updates are installed correctly if you have auto-update on, or make sure to manually download the patches as soon as possible otherwise. The Talos blog also has a rundown of Snort rules that can detect the exploitation of many of the vulnerabilities Microsoft disclosed this week. 

Top security headlines of the week 

U.S. intelligence agencies are warning that the Royal ransomware group could soon be headed for a rebrand and may already be operating under the name “BlackSuit.” Government sanctions have previously limited Royal’s ability to make money off their ransomware attacks, but new research from private firms and government agencies indicate that Royal may be connected to BlackSuit, another threat actor that uses similar open-source tools. Royal is a prolific ransomware group that the FBI says is responsible for infecting more than 350 companies, generating revenue in excess of $275 million. Security researchers are also speculating that Royal may have formed from the splintering of the former Conti ransomware gang, which was also the victim of sanctions and government takedown efforts. The U.S. and U.K. announced sanctions against 11 individuals believed to be a part of Conti in September. (TechCrunch, The Register

Fighting election misinformation has only gotten more difficult since the 2020 presidential election. New reporting and testimony indicate that many key programs and partnerships dedicated to fighting fake news and disinformation online have eroded over the past few years after political attacks from right-wing leaders and organizations. FBI Director Chris Wray told a Senate committee last week that an alliance of federal agencies, tech companies, election officials and security researchers dedicated to fighting foreign propaganda has fallen apart recently, with little to no communication between the various parties involved. Other officials in charge of fighting election disinformation say its been months since they heard from the FBI after once connecting with the agency regularly about fighting fake news on social media platforms. Additionally, many poll workers and election officials are afraid to discuss the topic after years of online pushback from right-wing voters who view the word “misinformation” as a synonym for censorship. (NBC News, NPR

Chip makers Intel and AMD disclosed new vulnerabilities this week that could lead to privilege escalation. Some Intel CPUs are vulnerable to the newly discovered “Reptar” vulnerability (CVE-2023-23583) that was disclosed on Tuesday. Adversaries can exploit this high-severity flaw if they already have access to the targeted system, eventually causing a crash on the machine leading to privilege escalation or the disclosure of sensitive system information. Another attack on AMD CPUs called “CacheWarp” could allow an attacker to infiltrate encrypted virtual machines and perform privilege escalation. This vulnerability, identified as CVE-2023-20592, affects AMD's Secure Encrypted Virtualization (SEV) technology. Users do not need to take any additional actions to address these vulnerabilities other than ensuring drivers and operating systems are up-to-date and patched. (SecurityWeek, The Hacker News

Can’t get enough Talos? 

Rather than putting a bunch of links here this week, I instead encourage you to watch this whole segment from Fox 11 in Los Angeles, featuring Nick Biasini from Talos Outreach. The story covers online scams, but features Nick discussing Talos’ recent research into various scams in the online video game “Roblox.” 

Upcoming events where you can find Talos 

misecCON (Nov. 17) 

Lansing, Michigan 

Terryn Valikodath from Talos Incident Response will deliver a talk providing advice on the best ways to conduct analysis, learning from his years of experience (and mishaps). He will speak about the everyday tasks he and his Talos IR teammates must go through to properly perform analysis. This talk covers topics such as planning, finding evil, recording findings, correlation and creating your own timelines. 

"Power of the Platform” by Cisco (Dec. 5 & 7) 

Virtual (Please note: This presentation will only be given in German) 

The annual IT event at the end of the year where Cisco experts, including Gergana Karadzhova-Dangela from Cisco Talos Incident Response, discuss the future-oriented topics in the implementation of digitalization together with you.  

Most prevalent malware files from Talos telemetry over the past week  

SHA 256: 0e2263d4f239a5c39960ffa6b6b688faa7fc3075e130fe0d4599d5b95ef20647 
MD5: bbcf7a68f4164a9f5f5cb2d9f30d9790 
Typical Filename: bbcf7a68f4164a9f5f5cb2d9f30d9790.vir 
Claimed Product: N/A 
Detection Name: Win.Dropper.Scar::1201 

SHA 256: b9ddbd1a4cec61e6b022a275d66312b5b676f9a0a9537a7708de9aa8ce34de59 
MD5: 3b100bdcd61bb1da816cd7eaf9ef13ba 
Typical Filename: vt-upload-C6In1 
Claimed Product: N/A  
Detection Name: Backdoor:KillAV-tpd 

SHA 256: 1fa0222e5ae2b891fa9c2dad1f63a9b26901d825dc6d6b9dcc6258a985f4f9ab 
MD5: 4c648967aeac81b18b53a3cb357120f4 
Typical Filename: yypnexwqivdpvdeakbmmd.exe 
Claimed Product: N/A  
Detection Name: Win.Dropper.Scar::1201 

SHA 256: a31f222fc283227f5e7988d1ad9c0aecd66d58bb7b4d8518ae23e110308dbf91  
MD5: 7bdbd180c081fa63ca94f9c22c457376 
Typical Filename: c0dwjdi6a.dll 
Claimed Product: N/A  
Detection Name: Trojan.GenericKD.33515991 

SHA 256: bea312ccbc8a912d4322b45ea64d69bb3add4d818fd1eb7723260b11d76a138a 
MD5: 200206279107f4a2bb1832e3fcd7d64c 
Typical Filename: lsgkozfm.bat 
Claimed Product: N/A 
Detection Name: Win.Dropper.Scar::tpd 

Text extracted automatically; images, tables and formatting may be missing. Original: https://blog.talosintelligence.com/threat-source-newsletter-nov-16-23/