SANS NewsBites

NB: 80 Million Malicious Chrome Extensions Installed; Qualcomms Snapdragon Chip FlawS Affect Millions of Android Devices; FBI: Hackers Exploiting F5s BIG-IP

August 11, 2020  |  Volume XXII - Issue #63

Top of the News


2020-08-07

Malicious Chrome Extensions Have More Than 80 Million Installs

Nearly 300 malicious extensions were found to be available in the Google Chrome Web Store. The extensions include phony utilities and ad blockers that inject ads into search results or engage in cookie stuffing. Google removed the extensions after a blog post from AdGuard. The extensions in question have been downloaded 80 million times.

Editor's Note

These extensions are attractive to end-users because they claim to solve problems such as blocking ads. Unfortunately, they hide their malicious behavior so it may not be evident for a while. Consider using the Chrome Admin Console to manage your enterprise Chrome browsers, including extensions. In general run only needed and verified extensions in your browser to minimize the attack surface and keep security as close to out-of-the box as possible.

Lee Neely
Lee Neely

Browser market share statistics are all over the place, but Chrome has something like 60% of the browser market, probably around 2 billion active users. So, only about 4% of active users downloaded any of those extensions. At one point there were close to 200,000 extensions in the Chrome Web Store, so 300 malicious extensions is 0.15% of the total. In April, Google announced new and more restrictive/security-centric rules for developers and gave them a deadline of 27 August to comply. We need to see what progress is made in reducing that percentage in September.

John Pescatore
John Pescatore

The purpose of sites like the Google Webstore should be to provide a selection of known good Chrome extensions. Google has repeatedly failed at this task. Researchers regularly find large numbers of malicious extensions. Google has changed the approval process, but it appears all they accomplished is to antagonize the developers of valid extension without solving the problem of malicious or questionable extensions.

Johannes Ullrich
Johannes Ullrich

2020-08-08

Vulnerabilities in Qualcomms Snapdragon Chip Affect Android Devices

Flaws in Qualcomm Snapdragon chips could be exploited to monitor location and audio and to steal images and videos. They could also be exploited to render devices useless. The chips are used in hundreds of millions of Android devices.

Editor's Note

This is a system on a chip (SOC) vulnerability in Qualcomms Digital Signal Processing (DSP) chip used to enhance charging, multimedia, and audio activities. The fix will require updates from the hardware manufacturer. There is no evidence of active exploit at this time. Mitigate risks by controlling physical possession of your device, keeping it updated, and leveraging play protect to install vetted applications. Coincidentally, Samsung has released a number of fixes for critical vulnerabilities; while those fixes do not include the DSP CVEs, you should apply them regardless.

Lee Neely
Lee Neely

These flaws could haunt Android users (and manufacturers of devices) for a while. It isnt clear how or even whether they will be patched. Even if they will be patched, the process will take a while.

Johannes Ullrich
Johannes Ullrich

2020-08-10

FBI: Hackers are Attempting to Exploit Known Vulnerability in F5s BIG-IP

In a security alert sent to private sector partners last week, the FBI warned that hackers are actively trying to exploit a known flaw in F5s BIG-IP networking device. The FBI did not identify the hacking group, but sources have said that the attacks are being perpetrated by a hacking group, known as Fox Kitten or Parisite, with ties to Iran.

Editor's Note

If you're having trouble getting your support staff to apply the updates from F5, you may wish to mention this to management, particularly for your internet-facing services.

Lee Neely
Lee Neely

The Rest of the Week's News


2020-08-07

Bulgarian Police Arrest Hacker

Authorities in Bulgaria have arrested a man for alleged hacking, extortion, and selling stolen data. According to a Ministry of Interior press release, authorities seized equipment from the suspects home.


2020-08-07

Ohio Secretary of State Has a Vulnerability Disclosure Policy for Election-Related Site

Ohio is the first US state to establish a vulnerability disclosure policy for its election-related websites. The policy from Ohio's secretary of state lays out guidelines, including which sites the policy covers, what types of testing are not permitted, and what information vulnerability reports should include. Vulnerability hunters are required to wait 120 days after reporting vulnerabilities to publicly disclose details.

Editor's Note

his is an outstanding step forward for Ohio. The long disclosure window of 120 days will result in early disclosure by those used to the more common 30-90 day window. One hopes low-hanging fruit issues are identified quickly to enable the state to improve its security posture for the upcoming election.

Lee Neely
Lee Neely

120 days is long compared the 30-90 days that commonly accepted responsible vulnerability disclosure recommendations specify, and this does push public disclosure beyond the 2020 election cycle. Realistically, this seems reasonable for the complex and fractured way election systems are developed, procured and run at local levels. At this late point, basic security hygiene (including segmentation and mitigation) needs to be the focus.

John Pescatore
John Pescatore

The motivation of "research" should be to improve quality, in this case of a socially and politically sensitive application, not to enhance the reputation, not to say notoriety, of the "researcher." Public shaming may have a place but this is not it. I know of no other field that engages in this destructive competition.

William Hugh Murray
William Hugh Murray

2020-08-10

TeamViewer Releases Updates to Address High-Severity Flaw

A vulnerability in the Desktop for Windows desktop app version of TeamViewer remote support software could be exploited to execute code and access password hashes. The flaw exists because the app does not properly quote its custom URI handlers. The vulnerability affects versions of TeamViewer Desktop for Windows prior to 15.8.3. TeamViewer has released updates for multiple versions of the software to fix the problem.


2020-08-10

Travelex Now in Administration, Forced to Eliminate 1,300 Jobs in UK

Currency exchange company Travelex is now in administration, the UK equivalent of bankruptcy. The restructuring plan includes eliminating 1,300 jobs in the UK. The currency exchange company suffered a ransomware attack in late December 2019 and was not able to resume conducting business until January 17, 2020. The onset of the COVID pandemic took a toll on the business as well.

Editor's Note

After a ransomware attack, business recovery is complex. Economic impact of the recovery, reputation of the business, and continued customer support, or lack thereof, can make or break you. When your primary customer base, in this case the travel industry, shuts down right after you are back on-line, partnerships and restructuring are needed to survive. For many of us, Travelexs reputation as a known quantity in currency exchange while traveling will help them recover.

Lee Neely
Lee Neely

This suggests that current standards of "hygiene" are not sufficient to protect the business from an increasingly hostile public network. Do not bet your business.

William Hugh Murray
William Hugh Murray

2020-08-10

vBulletin Releases Fixes to Address Patch Bypass Flaw

An as-yet unpatched vulnerability in vBulletin can be exploited to run malicious code and take control of forums without authentication. The issue lies in a patch issued in September 2019. Proof-of-concept exploit code for the vulnerability bypasses the protections put in place by the earlier patch. The vulnerability is being actively exploited. vBulletin has released a fix as well as suggestions for mitigation.


2020-08-10

Mystery Threat Actor Operated 25 Percent of Tor Exit Nodes

An unidentified threat actor has been adding servers to the Tor network since January 2020. By May, they were operating 380 Tor exit relays, a quarter of all exit relays. The group is conducting SSL stripping attacks, downgrading traffic from HTTPS to HTTP in an attempt to steal cryptocurrency by replacing Bitcoin addresses in the traffic.

Editor's Note

The actor was taking advantage of insufficient vetting processes for adding exit relays. While many of the malicious relays have been reported and shut down, as of August 8th, the threat actor still controlled 10% of the Tor exit relays. SSL stripping attacks can be prevented by setting up HSTS preload for your domain; many sites have not done this. Browsers which are not by default marking HTTP traffic insecure may benefit by installing a plugin such as HTTPS Everywhere, which enforces HTTPS use by rewriting headers on the fly.

Lee Neely
Lee Neely

Users should be aware that Tor does a better job of hiding the origin of traffic, what it was built for, than it does of protecting the traffic itself.

William Hugh Murray
William Hugh Murray

Internet Storm Center Tech Corner

Scanning Activity Against WIFICAM Using Netcat

https://isc.sans.edu/forums/diary/Scanning+Activity+Include+Netcat+Listener/26442/


Small Challenge: A Simple Word Maldoc (Solution)

https://isc.sans.edu/forums/diary/Small+Challenge+A+Simple+Word+Maldoc+Part+2/26444/


Scoping Web Application Pentests

https://isc.sans.edu/forums/diary/Scoping+web+application+and+web+service+penetration+tests/26448/


PDF Test Suite

https://github.com/RUB-NDS/PDF101

https://raw.githubusercontent.com/RUB-NDS/PDF101/master/eval.png


Qualcomm Snapdragon Vulnerabilities

https://blog.checkpoint.com/2020/08/06/achilles-small-chip-big-peril/


China Blocking TLS 1.3 and ESNI

https://gfw.report/blog/gfw_esni_blocking/en/


Problems With Chrome Extensions

https://adguard.com/en/blog/fake-ad-blockers-part-3.html


TeamViewer Update

https://community.teamviewer.com/t5/Announcements/Statement-on-CVE-2020-13699/m-p/99129