Tag Archives: Internet of Things

VPNFilter: Overview and removal

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Update: 24th October 2018:
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Researchers from Cisco’s Talos team have discovered further capabilities of this malware. As detailed below the 3rd stage of the malware features:

Provides plugins for the RAT (defined below in the original post) to extend its functionality.

However, the team was able to determine the following extra capabilities:

  1. Packet sniffing (obtain information from passing data packets (defined) on a network connection)
  2. JavaScript (defined) injection used to deliver exploit (a small piece of software used to trigger a known vulnerability to the advantage of an attacker) to a compromised device (most likely a router).
  3. Encrypted tunnelling (defined) to hide data the malware steals as well as the existing command and control data traffic.
  4. Creating network maps (defined)
  5. Remote connection/administration via SSH (Secure Shell)(defined)
  6. Port forwarding (defined)
  7. Create SOCK5 (defined) proxies (defined)
  8. DDoS (defined)

The good news about this malware is that from the Talos team’s research it does not appear that any malware samples remain active. However; they caution it is not possible to assume that this malware has finished its malicious actions and the possibility of its return remains.

Thank you.

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Update: 20th June 2018:
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If you would prefer a video or a podcast of how to remove this malware from your router, this Sophos blog post provides links to both. The video is hosted on Facebook but a Facebook account isn’t required to view it. Sophos also provide an archive of previous videos on the same Facebook page.

Thank you.

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Update: 6th June 2018:
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The Cisco Talos team have provided an updated list of known affected routers. I have added these to the list below with “(new)” indicating a new device on the existing list. I have also updated the malware removal advice to provide easier to follow steps.

Thank you.

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Original Post:
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In late May; a strain of malware known as VPNFilter affecting routers from the vendors listed below was publicly disclosed by the Cisco Talos team:

Affected vendors:
Asus RT-AC66U (new)
Asus RT-N10 (new)
Asus RT-N10E (new)
Asus RT-N10U (new)
Asus RT-N56U (new)
Asus RT-N66U (new)
D-Link DES-1210-08P (new)
D-Link DIR-300 (new)
D-Link DIR-300A (new)
D-Link DSR-250N (new)
D-Link DSR-500N (new)
D-Link DSR-1000 (new)
D-Link DSR-1000N (new)
Huawei HG8245 (new)
Linksys E1200
Linksys E2500
Linksys E3000 (new)
Linksys E3200 (new)
Linksys E4200 (new)
Linksys RV082 (new)
Linksys WRVS4400N
Mikrotik CCR1009 (new)
Mikrotik Cloud Core Router (CCR) CCR1016
Mikrotik CCR1036
Mikrotik CCR1072
Mikrotik CRS109 (new)
Mikrotik CRS112 (new)
Mikrotik CRS125 (new)
Mikrotik RB411 (new)
Mikrotik RB450 (new)
Mikrotik RB750 (new)
Mikrotik RB911 (new)
Mikrotik RB921 (new)
Mikrotik RB941 (new)
Mikrotik RB951 (new)
Mikrotik RB952 (new)
Mikrotik RB960 (new)
Mikrotik RB962 (new)
Mikrotik RB1100 (new)
Mikrotik RB1200 (new)
Mikrotik RB2011 (new)
Mikrotik RB3011 (new)
Mikrotik RB Groove (new)
Mikrotik RB Omnitik (new)
Mikrotik STX5 (new)
Netgear DG834 (new)
Netgear DGN1000 (new)
Netgear DGN2200
Netgear DGN3500 (new)
Netgear FVS318N (new)
Netgear MBRN3000 (new)
Netgear R6400
Netgear R7000
Netgear R8000
Netgear WNR1000
Netgear WNR2000
Netgear WNR2200 (new)
Netgear WNR4000 (new)
Netgear WNDR3700 (new)
Netgear WNDR4000 (new)
Netgear WNDR4300 (new)
Netgear WNDR4300-TN (new)
Netgear UTM50 (new)
QNAP TS251
QNAP TS439 Pro
Other QNAP NAS devices running QTS software
TP-Link R600VPN
TP-Link TL-WR741ND (new)
TP-Link TL-WR841N (new)
Ubiquiti NSM2 (new)
Ubiquiti PBE M5 (new)
UPVEL Unknown Models* (new)
ZTE ZXHN H108N (new)

Why should this malware be considered important?
The authors (thought to be a group funded by a nation state) of this malware are using it to hijack vulnerable routers (500,000 are known to have been compromised across 54 countries) for possible use in cyberattacks against the Ukraine. Indeed, the malware more recently began seeking out Ukrainian routers specifically. The Ukrainian Secret Service issued a security alert on this on the 23rd of May.

The malware has the ability to do so by utilising previously publicly disclosed (defined) vulnerabilities to gain access and persistence (namely remaining present after the router is powered off and back on) within these routers. Last week the FBI took control of this botnet and are now working to clean up the affected devices.

The malware is very sophisticated and can persist within a router even if the router is powered off and back on (becoming the second malware to have this ability, the first being the Hide and Seek botnet). The malware is made up of 3 stages:

Stage 1: Is responsible for the persistence (mentioned above).
Stage 2: Providing the capabilities of a remote access Trojan (RAT)(defined)
Stage 3: Provides plugins for the RAT to extend it’s functionality.

The malware also has the capability to do the following:

  1. Wipe the firmware (see Aside below for a definition) of routers rendering them useless
  2. Inspect the data traffic passing through the router (with the possible intention of obtaining credentials passing over the wire to gain access to sensitive networks)
  3. Attempt to locate ICS/SCADA devices (defined) on the same network as the router by seeking out port 502 traffic, namely the Modbus protocol (defined) with the option of deploying further malware
  4. Communicate via the Tor network (definition in the Aside below).

How can I protect my devices from this malware?
The FBI are asking anyone who suspects their internet router to be infected to first reboot it (turn on and off the router). This will cause an infected device to check-in with the now under FBI control C&C (command and control, C2 (defined) server to provide them with a better overview of the numbers of infected devices.

To completely remove the malware; reset the device to factory defaults (this won’t harm a non-infected either but please ensure you have the necessary settings to hand to re-input them into the router, your internet service provider (ISP) will be able to help with this). This will remove stage 1 of the malware (stage 2 and 3 are removed by turning the router on an off).

To prevent re-infection: Cisco Talos’ team recommendations are available from this link. Moreover the US CERT provide recommendations here and here. Symantec’s recommendations are provided here (especially for Mikrotik and QNAP devices).

Further advisories from router manufacturers are as follows (their advice should supersede any other advice for your router model since they know their own devices the best):

Linksys
MiktroTik
Netgear
QNAP
TP-Link

Further recommendations from Sophos are:

  • Check with your vendor or ISP to find out how to get your router to do a firmware update.
  • Turn off remote administration unless you really need it
  • Choose strong password(s) for your router
  • Use HTTPS website where you can

A very useful and easy to follow step by step walk through of removing this malware by BleepingComputer is available from this link with useful guidance for multiple router models.

Thank you.

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References:
New VPNFilter malware targets at least 500K networking devices worldwide : Cisco Talos team
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Aside:
What is firmware?
Firmware is semi-permanent embedded software code that allows a device to carry out its function by having the low-level hardware carry out useful sequences of events.

What is The Onion Router (Tor)?
The Onion Router (Tor) is an open source (defined) project with the goal of protecting your privacy by passing your web browsing activity through a series of anonymous relies spread across the internet. These relays act like proxy servers which encrypt and randomly pass the traffic they receive from relay to relay.

This web of proxies is sometimes referred to as the Dark web (a portion of the internet only accessible using the Tor network). This makes tracing the source of the source almost impossible.
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WPA2 KRACK Vulnerability: What you need to know

Last Sunday, the early signs of a vulnerability disclosure affecting the extensively used Wi-Fi protected access (WPA2) protocol were evident. The next day, disclosure of the vulnerability lead to more details. The vulnerability was discovered by  two researchers Mathy Vanhoef and Frank Piessens of the Katholieke Universiteit Leuven (KU Leuven) while examining OpenBSD’s implementation of the WPA2 four way handshake.

Why should this vulnerability be considered important?
On Monday 16th October, the KRACK (key re-installation attacks) vulnerability was disclosed. This vulnerability was found within the implementation of the WPA2 protocol rather than any single device making it’s impact much more widespread. For example, vulnerable devices include Windows, OpenBSD (if not already patched against it), Linux, Apple iOS, Apple macOS and Google Android.

If exploited this vulnerability could allow decryption, packet replay, TCP connection hijacking and if WPA-TKIP (defined) or GCMP (explained) are used; the attacker can inject packets (defined) into a victim’s data, forging web traffic.

How can an attacker exploit this vulnerability?
To exploit the vulnerability an attacker must be within range of a vulnerable Wi-Fi network in order to perform a man in the middle attack (MiTM)(defined). This means that this vulnerability cannot be exploited over the Internet.

This vulnerability occurs since the initial four way handshake is used to generate a strong and unique key to encrypt the traffic between wireless devices. A handshake is used to authenticate two entities (in this example a wireless router and a wireless device wishing to connect to it) and to establish the a new key used to communicate.

The attacker needs to manipulate the key exchange (described below) by replaying cryptographic handshake messages (which blocks the message reaching the client device) causing it to be re-sent during the third step of the four way handshake. This is allowed since wireless communication is not 100% reliable e.g. a data packet could be lost or dropped and the router will re-send the third part of the handshake. This is allowed to occur multiple times if necessary. Each time the handshake is re-sent the attacker can use it to gather how cryptographic nonces (defined here and here) are created (since replay counters and nonces are reset) and use this to undermine the entire encryption scheme.

How can I protect myself from this vulnerability?
AS described in this CERT knowledge base article.; updates from vendors will be released in the coming days and weeks. Apple (currently a beta update) and Microsoft already have updates available. OpenBSD also resolved this issue before the disclosure this week.

Microsoft within the information they published for the vulnerability discusses how when a Windows device enters a low power state the vulnerable functionality of the wireless connection is passed to the underlying Wi-Fi hardware. For this reason they recommend contacting the vendor of that Wi-Fi hardware to request updated drivers (defined).

Links to affected hardware vendors are available from this ICASI Multi-Vendor Vulnerability Disclosure statement. Intel’ security advisory with relevant driver updates is here. The wireless vendor, Edimax also posted a statement with further updates to follow. A detailed but easy to use list of many vendors responses is here. Since I use an Asus router, the best response I could locate is here.

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Update: 21st October 2017:
Cisco have published a security advisory relating to the KRACK vulnerability for its wireless products. At the time of writing no patches were available but the advisory does contain a workaround for some of the affected products.
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The above updates are software fixes but updates will also be made available for devices in the form of firmware updates e.g. for wireless routers, smartphones and Internet of Things (IoT)(defined) devices. For any wireless devices you own, please check with the manufacturer/vendor for available updates with the above CERT article and vendor response list detailing many of the common vendors.

Thank you.

Infineon TPM Chips Patched Against Disclosed Vulnerability

With the release of Microsoft’s security updates last week; Infineon published a security advisory relating to a vulnerability discovered by security researchers in 2012.

Why should this vulnerability be considered important?
The vulnerable hardware is mostly to be found within corporate computers from manufacturers such as HP, Fujitsu and Lenovo. Google Chromebooks, routers and some Internet of Things (IoT)(defined). The vulnerability allows an attacker to determine a private (defined) encryption key when it has been generated by a vulnerable TPM (Trusted Platform Module) using only the public key (defined). Once the private key has been obtained it can be used by an attacker to decrypt the contents of a Microsoft BitLocker encrypted hard drive, to digitally sign fake software releases, to sign malware (making it appear more legitimate) as well impersonating the legitimate owner of the private key.

This vulnerability also affects cryptographic smart cards, security tokens and other secure hardware chips manufactured by Infineon. An estimate 760k devices are thought to be vulnerable while the true number could be up to three times that amount.

While the researchers were able to verify an attacker could derive the private key from 1024 and 2048 but public key, they were unable to do so for 4096 bit key since “a 4096-bit RSA key is not practically factorizable now, but “may become so, if the attack is improved.” For 1024 and 2048 bit keys, the factorisation can be easily parallelised by x number of CPUs, reducing the time taken by x times (where x is the number of cores a CPU has) allowing completion in hour or days.

How can I protect myself from this vulnerability?
Microsoft’s advisory provides the recommended steps for systems using Windows or other Microsoft products e.g. Active Directory Certificate Services (ADCS), Active Directory Directory Services (ADDS) (among others). The updates they recommend are only a workaround for the vulnerability. The vulnerability must still be resolved by applying updates to the vulnerable TPM chips. This advice also includes clearing the TPM and re-generating the necessary keys only after applying the updates from Microsoft.

Similarly Google made available Chrome OS M60 to mitigate this vulnerability. Further links to other affected vendors are listed below:

Fujitsu

HP Customer Support

HP Enterprise Support

Lenovo

Toshiba

Thank you.

BlueBorne : Bluetooth Vulnerability Explained

Researchers from the security firm Armis have discovered a set of eight security vulnerabilities within the Bluetooth (defined) communications technology and responsibly disclosed (defined) them to affected device manufacturers. These are not present in the protocol layer of Bluetooth but within the implementation layer of Bluetooth which “bypasses the various authentication mechanisms, and enabling a complete takeover of the target device” (source). An estimated 5.3 billion devices are thought to be vulnerable ranging from computers tablets, smartphone, TVs, watches to Internet of Things (IoT) (defined) medical devices. This set of vulnerabilities is known as “BlueBorne”.

What is BlueBorne and why is it important?
Exploitation of the BlueBorne vulnerabilities allows the complete compromise of the vulnerable device and does not require the vulnerable device be paired (defined) with the attacking device.

Once exploited the vulnerabilities allow the attacker to conduct remote code execution (defined: the ability for an attacker to remotely carry out any action of their choice on your device)) and man in the middle attacks (defined). To begin the attack, the attacker does not need for the user of the vulnerable device to have taken any action.

These vulnerabilities are particularly severe since Bluetooth is less secured on a corporate network than for example, the proxy server (defined) providing internet access making spreading from advice to device in a worm (defined) like fashion (theoretically) possible. The Bluetooth protocol often runs with high privilege on devices and is not usually considered a potential entry point into a network. Air gapped systems (defined) are also potentially vulnerable.

How can I protect myself from these issues?
Software updates for some devices are listed here (for Google, Linux and Microsoft devices). Recent Apple devices were found not to be vulnerable. A full list of affected devices and the software updates to protect them are listed here and will be updated by Armis.

For users of Google Android devices, they can check if their device is vulnerable by downloading the BlueBorne Android app. Disabling Bluetooth if you are not using it and only leaving it enabled for the time you are using it are also good security practices. Once your devices are updated, you should be able to resume normal Bluetooth usage. Please not that not all devices will or can be updated due to end of support lifecycles, newer products and product limitations. It is estimated approximately 2 billion devices will not receive software updates to resolve these issues.

Thank you.

Internet of Things malware destroys devices

In early April embedded devices powered by Google Android, Linux and FreeBSD (specifically the BusyBox distribution) mainly used as media players and routers came under attack from a previously unseen form of malware.

How does this malware affect compromised devices?
Once compromised the device will cease functioning within seconds; an attack being called a PDoS (Permanent Denial of Service). This occurs since the malware corrupts the devices internal storage and reduces the number of kernel (defined) threads (sequences of independent in progress tasks) from several thousand to just one, causing the devices in progress tasks/work load to halt. Security firm Radware demonstrated this result with a webcam.

How does this malware initially compromise a device?
Since early April four unique versions of this malware (dubbed BrickerBot) have emerged. The first version attempted to compromise Radware’s test device almost 2,000 times within four days with the attacks originating from all over the world. The second and more advanced version uses Tor (The Onion Router) to enable attacks to take place from the Dark web (a portion of the internet only accessible using the Tor network). This makes tracing the source of the attacks almost impossible.

Versions 3 targets further devices while version 4 was active during a very briefly and ceased its activity after 90 attempted attacks. Radware provide more details in their analysis.

The malwares authors seek to gain control of vulnerable devices by attempting to access them over the internet via the Telnet protocol (defined, which uses TCP and UDP ports 23) by entering commonly used usernames and passwords until successful. If your network contains routers or music/media devices using the BusyBox distribution they are potentially vulnerable to this malware. Attackers can use tools such as Shodan (defined) to locate vulnerable devices over the internet and begin an attack.

How can I protect my devices from this malware?
Radware provide five steps you can take to better secure your internet of things (IoT , defined) devices from this malware. They also suggest the use of an IPS (defined) in this related blog post. The above recommendations are especially important since unlike other malware where you can re-format a hard disk and re-install the operating system (defined), this malware permanently damages the device and it will require a replacement.

Thank you.

Mitigating the Increasing Risk Facing Critical Infrastructure and the Internet of Things

With attackers and malware authors extending their reach to more and more areas of our everyday lives, both companies and individuals need to take steps to improve the security of their equipment/devices. It’s not just devices such as thermometers (while important) in our homes at risk; devices that impact health and safety as well as entire communities and economies are being / or will be targeted.

For example, last month a cyber-attack took place in Ukraine that while it only lasted approximately 1 hour, served to cause a power outage in an entire district of Kiev. The on-going investigation into this attack believes it to be the same attackers responsible for the December 2015 attack (that attack affected approximately 250,000 people for up to 6 hours).

In a similar manner, a smaller energy company (at an undisclosed location) was a victim of the Samsam ransomware (defined). The attackers initially compromised the web server and used a privilege escalation vulnerability (defined) to install further malware and spread throughout the network. The attackers demanded 1 Bitcoin per infected system. The firm paid the ransom and received a decryption key that didn’t work.

Fortunately, this energy company had a working backup and was back online after 2 days. The root cause of infection? Their network not being separated by a DMZ (defined) from their industrial networks. This Dark Reading article also details 2 further examples of businesses affected who use industrial systems namely a manufacturing plant and a power plant. Both were located in Brazil.

Mark Stacey of RSA’s incident response team says that while nation states have not yet employed ransomware in industrial systems, it will certainly happen. He cites the example of a dam, where the disabling of equipment may not demand a large ransom compared to the act of encrypting the data required for its normal operation.

Former US National Security Official Richard Clarke is suggesting the use of a tried and tested means of increasing the security of all deployed industrial control systems. As it is very difficult convincing those on the Board of Directors to provide budget for something that has not happened/may not happen, he suggests employing an approach similar to that of the Y2K bug. This would require introducing regulations that require all devices after a given date be in a secured state against cyber-attack. He advocates electric power, connected cars and healthcare providers follow this approach and notes that without regulation “none of this is going to happen.” Since these regulations would apply to all ICS/SCADA (defined) vendors, they would also not loose competitiveness

With security analysts predicting further compromises of ICS/SCADA equipment this year, we need to better protect this infrastructure.

For enterprises and businesses, the regulations proposed above should assist with securing IoT and ICS/SCADA devices. However, this is just the beginning. This scanner from Beyond Trust is another great start. As that article mentions the FTC is offering $100,000 to “a company that can discover an innovative way of managing and patching IoT devices.” Securing IoT devices is not an easy problem to solve.

However, progress is happening with securing critical infrastructure and Internet of Things (IoT)(defined) devices. For example, please find below resources/recommendations, tools and products that can help protect these systems and devices.

How can we better secure ICS/SCADA devices?
These devices power our critical infrastructure e.g. power, gas, communications, water filtration etc. The US ICS-CERT has a detailed list of recommendations available from the following links:

ICS CERT Recommended Practices
ICS-CERT Secure Architecture Design
ICS Defense In-Depth (PDF)

An ICS-CERT overview of the types of vulnerabilities that these systems face.

Securing IoT devices in industry
Free IoT Vulnerability Scanner Hunts Enterprise Threats (Dark Reading.com)
Defending the Grid
Network and IoT to underpin Trend Micro’s 2017 strategy

Securing IoT in the medical sector/businesses
Hospitals are under attack in 2016 (Kaspersky SecureList)
Fooling the Smart City (Kaspersky SecureList)

Recommendations for consumer IoT devices are the following
My previous recommendations on securing IoT devices
Blog Post Shout Out: New Wireless Routers Enhance Internet of Things Protection
Securing Your Smart TV
8 tips to secure those IoT devices (Network World)
Who Makes the IoT Things Under Attack? (Krebs on Security)

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I hope that you find the above resources useful for securing ICS/SCADA as well as IoT devices that are very likely a target this year.

Thank you.

Protecting Your Smart TV From Ransomware

In mid-2016 a news article detailed the possibility for Android powered Smart TVs to be infected by ransomware. Last month that prediction came true.

To recover the affected TV, you should reset it to factory default settings. You may need to contact the manufacturer if they don’t provide the steps to perform the reset as part of the devices documentation.

With 2017 predicted to break the record set in 2016 for ransomware, occurrences such as this will likely become more common.

Unfortunately, TV manufacturers are unlikely to pre-harden vulnerable devices before shipping them due to compatibility concerns and increased costs (during manufacturing and later support costs). To increase use of their after sales service they are again unlikely to publish the key sequences or button presses to perform a factory reset.

The ransomware encountered by this software developer was “just” a screen locker. It didn’t also try to encrypt any connected USB drives. Separately, a Symantec security researcher published a helpful list of mitigations to protect against ransomware targeting Smart TVs.

Continuing the trend of protecting Internet of Things (IoT) devices (defined), I hope that you find the above mitigations useful. Please also refer to this previous blog post for more general advice on preventing ransomware infections on your everyday computing devices (non IoT devices).

Thank you.