Threats directed at telecoms companies
Threats targeting telecommunication companies directly. These include DDoS attacks, targeted attacks (APT campaigns), network device vulnerabilities and human-related threats like insider access, social engineering and the risk of allowing third parties to access information.
DDoS (distributed denial of service) attacks remain a serious threat to telecoms providers around the world as attackers discover ever more ways of boosting the power and scale of attacks. Kaspersky Lab’s DDoS intelligence report for Q2, 2016 notes that websites in 70 countries were targeted with attacks. By far the most affected country was China, with South Korea and the US also among the leaders. 70.2% of all detected attacks were launched from Linux botnets, with cybercriminals paying close attention to financial institutions working with cryptocurrency. Another trend observed in Q2 was the use of vulnerable IoT devices in botnets to launch DDoS attacks.
The telecommunications sector is particularly vulernable to DDoS attacks. According to the 2016 Data Breach Investigations Report, the telecommunications sector was hit around twice as hard as the second placed sector (financial exchanges), with a median DDoS packet count of 4.61 million packets per second (compared to 2.4 Mpps for exchanges.)
The impact of a DDoS attack should not be underestimated. Direct attacks can reduce network capacity, degrade performance, increase traffic exchange costs, disrupt service availability and even bring down Internet access if ISPs are affected. With a growing number of connected devices and systems supporting mission-critical applications in areas such as healthcare and transport, unexpected downtime could be life threatening.
Further, DDoS attacks can be a cover for a deeper, more damaging secondary attack, or a route into a key enterprise subscriber or large-scale ransomeware attack.
A good example of the first is the 2015 cyber-attack on the UK telecoms company, TalkTalk. The hack, alledgedly perpetrated by a couple of teenagers, resulted in the loss of around 1.2 million customers’ email addresses, names and phone numbers, as well as many thousands of customer dates of birth and financial information – all ideal for use in financially-motivated social engineering campaigns. The forensic investigation revealed that the hackers had used a smokescreen DDoS attack to conceal their main activities.
DDoS attacks are also evolving. 2015 saw attackers amplify the power of DDoS attacks by turning them into DrDoS (Distributed reflection Denial of Service) attacks through the use of standard network protocols like NTP, RIPv1, NetBIOS (Network Basic Input/Output System) and BGP (Border Gateway Patrol). Another approach that is becoming more commonplace is the compromise of end-user routers via network-scanning malware and firmware vulnerabilities. Today’s faster mobile data transfer speeds and the growing adoption of 4G are also making smartphone-based botnets more useful for implementing DDoS attacks.
The worrying thing is that even inexperienced attackers can organize quite an effective DDoS campaign using such techniques.
2. Targeted attacks
The core infrastructure of a telecommunications company is a highly desirable target for cybercriminals, but gaining access is extremely difficult. Breaking into the core requires a deep knowledge of GSM architecture, rarely seen except among the most skilled and resourced cybercriminals. Such individuals can generally be found working for advanced, international APT groups and nation-state attackers, entities that have a powerful interest in obtaining access to the inner networks of telecommunication companies. This is because compromised network devices are harder to detect by security systems and they offer more ways to control internal operations than can be achieved through simple server/workstation infiltration.
Once inside the core infrastructure, attackers can easily intercept calls and data, and control, track and impersonate subscibers.
Other APTs with telecommunications on their radar
The Regin APT campaign, discovered in 2014, remains of the most sophisticated ever seen and has the ability to infiltrate GSM networks, while the Turla group, has developed the ability to hijack satellite-based Internet links as part of it’s Command & Control process, successfully obscuring its actual location.
Others, such as Dark Hotel and a new cyber-espionage threat actor likely to be of Chinese origin, exploit telecoms networks in their targeted campaigns. In these cases, the telecoms providers often suffer collateral damage even though they are not directly related to the attack. Further details on these can be found on Kaspersky Lab’s expert Securelist blog or through a subscription to the Kaspersky APT Threat Intelligence Reporting service.
3. Unaddressed software vulnerabilities
Despite all the high profile hacks and embarrassing data leaks of the last 12 months, attackers are still breaching telecoms defenses and making off with vast quantities of valuable, personal data. In many cases, attackers are exploiting new or under-protected vulnerabilities. For example, in 2015, two members of the hacker group, Linker Squad gained access to Orange Spain through a company website vulnerable to a simple SQL injection, and stole 10 million items of customer and employee data.
4. The impact of service misconfiguration
In many cases, the hardware used by by the telecommunications industry carries configuration interfaces that can be accessed openly via HTTP, SSH, FTP or telnet. This means that if the firewall is not configured correctly, the hardware in question becomes an easy target for unauthorized access.
The risk presented by publicly exposed GTP/GRX (GPRS Tunneling Protocol/GPRS Roaming Exchange) ports on devices provides a good example of this.
As CSPs encrypt the GPRS traffic between the devices and the Serving GPRS Support Node (SGSN), it is difficult to intercept and decrypt the transferred data. However, an attacker can bypass this restriction by searching on Shodan.io for devices with open GTP ports, connecting to them and then encapsulating GTP control packets into the created tunnel.
Table 1. Top 10 countries with GTP/GRX ports exposed to Internet access
|#||Country||Number of GTP/GRX|
|3||United States of America||6.403|
|10||United Arab Emirates||808|
The Border Gateway Protocol (BGP) is the routing protocol used to make decisions on routing between autonomous systems. Acceptance and propagation of routing information coming from other peers can allow an attacker to implement man-in-the-middle (MITM) attacks or cause denial of service. Any route that is advertised by a neighboring BGP speaker is merged in the routing database and propagated to all the other BGP peers.
Table 2. Top five countries with BGP protocol exposed to Internet access
|#||Country||Number of devices
(end of 2015)
|1||Republic of Korea||16.209|
|3||United States of America||8.111|
An example of such an attack took place in March 2015, when Internet traffic for 167 important British Telecom customers, including a UK defense contractor that helps to deliver the country’s nuclear warhead program, was illegally diverted to servers in Ukraine before being passed along to its final destinations.
To avoid probable attacks against BGP from unauthorized remote malefactors, we recommend that companies provide network filtering, allowing only a limited number of authorized peers to connect to BGP services. To protect against malicious re-routing and hijacking initiated through authorized autonomous systems we recommend that they monitor anomalies in BGP communications (this can be done through specialized software solutions or by subscribing to alerts from vendors providing this kind of monitoring.)
5. Vulnerabilities in network devices
Routers and other network devices are also primary targets for attacks against telecommunications companies.
In September 2015, FireEye researchers revealed the router malware “SYNful knock”, a combination of leaked privilege (root) credentials and a way of replacing device firmware that targets Cisco 1841, 2811 and 3825 routers (see Cisco advisory here).
Put simply, SYNful knock is a modified device firmware image with backdoor access that can replace the original operating system if the attacker has managed to obtain privileged access to the device or can physically connect to it.
SYNful is not a pure software vulnerability, but a combination of leaked privileged credentials combined with a certain way of replacing device firmware. Still, it is a dangerous way of compromising an organization’s IT infrastructure.
SYNful knock backdoor sign-in credentials request
The latest information on the number of potentially compromised devices is available through the link https://synfulscan.shadowserver.org/stats/.
A second Cisco vulnerability, CVE-2015-6389 enables attackers to access some sensitive data, such as the password file, system logs, and Cisco PCA database information, and to modify data, run internal executables and potentially make the system unstable or inaccessible. Cisco Prime Collaboration Assurance Software releases prior to 11.0 are vulnerable. Follow this Cisco bulletin for remediation actions.
For further information on Cisco fixes for its devices see https://threatpost.com/cisco-warning-of-vulnerabilities-in-routers-data-center-platforms/115609.
Juniper, another network device manufacturer has been found to carry vulnerabilities in its operating system for its NetScreen VPN appliances, enabling third-party access to network traffic. The issue was reported by the vendor in the security advisory JSA10713 on December 18th, 2015, along with the release of the patch.
It appears that the additional code with hardcoded password was planted in the source code in late 2013. The backdoor allows any user to log in with administrator privileges using hard-coded password “<<< %s(un=’%s’) = %u”.This vulnerability has been identified as CVE-2015-7755 and is considered highly critical.
Top countries where ScreenOS devices are used are the Netherlands, the United States, China, Italy and Mexico.
Another Juniper backdoor, CVE-2015-7756, affects ScreenOS 6.2.0r15 through 6.2.0r18 and 6.3.0r12 through 6.3.0r20 and allows a third party to monitor traffic inside VPN connections due to security flaws in the Dual_EC PRNG algorithm for random number generation.
To protect the organization from misconfiguration and network device vulnerabilitiy, Kaspresky Lab recommendats that companies pay close attention to vulnerabilities in the network services of telecommunication equipment, establish effective vulnerability and configuration management processes, and regularly perform security assessments, including penetration testing for different types of attackers (a remote intruder, a subscriber, a contractor, etc.).
6. Malicious insiders
Even if you consider your critical systems and devices protected and safe, it is difficult to fully control some attack vectors. People rank at the very top of this list. Their motivations are often hard to predict and anticipate, ranging from a desire for financial gain to disaffection, coercion and simple carelessness.
While insider-assisted attacks are uncommon, the impact of such attacks can be devastating as they provide a direct route to the most valuable information.
Examples of insider attacks in recent years include:
- A rogue telecoms employee leaking 70 million prison inmate calls, many breaching client-attorney privilege.
- An SMS center support engineer who had intercepted messages containing OTP (One-Time Passwords) for the two-step authentication required to login to customer accounts at a popular fintech company. The engineer was found to be freely offering his services on a popular DarkNet forum.
For attackers, infiltrating the networks of ISPs and CSPs requires a certain level of experience – and it is often cheaper and easier to stroll across the perimeter with the help of a hired or blackmailed insider. Cybercriminals generally recruit insiders through two approaches: enticing or coercing individual employees with relevant skills, or trawling around underground message boards looking for an appropriate employee or former employee.
Employees of cellular service providers are in demand for fast track access to subscriber and company data or SIM card duplication/illegal reissuing, while staff working for Internet service providers are needed for network mapping and man-in-the-middle attacks.
A particularly promising and successful attack vector for recruiting an insider for malicious intrusion is blackmail.
Data breaches, such as the 2015 Ashley Madison leak reveal information that attackers can compare with other publically available information to track down where people work and compromise them accordingly. Very often, these leaked databases contain corporate email addresses, including those of telecommunication companies.
Further information on the emerging attack vectors based on the harvesting of Open Source Intelligence (OSINT) can be obtained using Kaspersky Lab’s customer-specific Intelligence Reporting services.
Originally posted by Kaspersky Lab on Securelist