2019 năm Canh Tý, ngồi đọc một bài viết phân tích malware. Đọc từ đầu đến cuối chẳng thấy một điểm sáng nào. Nếu so với malware viết thời 2000 thì cũng không khác nhiều lắm, thậm chí còn tồi hơn… The Mirai botnet scans for IoT devices on both ports 23 and 2323. Test TCP port 2323. Port 7547 is used by a remote management protocol known as either TR-069 or CWMP (Customer Premises Equipment WAN Management Protocol). Some ISPs use this protocol to re-configure your router/gateway/modem. VPNFilter là gì; Cách thức hoạt động của virus; giống như phần mềm độc hại Mirai, điều này có thể xảy ra do một cuộc tấn công botnet tự động chưa được thực hiện do thỏa hiệp thành công các máy chủ trung tâm. Sự lây nhiễm xảy ra thông qua một khai thác khiến Đầu tiên, BotenaGo chỉ là một mô-đun của bộ phần mềm độc hại lớn hơn hiện không được sử dụng trong các cuộc tấn công. Thứ hai, BotenaGo có khả năng được liên kết với Mirai, được sử dụng bởi những kẻ đứng sau Mirai khi nhắm mục tiêu vào các máy tính cụ thể. Váy bèo nhún. Rất đơn giản mẹ hãy lấy một chiếc váy của con làm mẫu đặt lên áo mẹ và cắt theo. Sau đó tận dụng phần thừa của áo cắt thành dải bèo nhún và làm thêm một chiếc nơ xanh làm điểm nhấn là đã đã có một chiếc váy cực sành điệu rồi. Ảnh: Kaviokid Đồ thị lời gọi hàm trong phát hiện mã độc IoT botnet Một đồ thị lời gọi hàm (FCG - Function Call Graph) là một đồ thị luồng điều khiển liên thủ tục, ở đó biểu diễn lời gọi quan hệ giữa các hàm hoặc chương trình con trong một chương trình thực thi. Định nghĩa một cách chính thức được thể hiện như định nghĩa 3.1. j4v8fac. Updated 04/21/2022 - 1226 Time to read 5 minutes Mirai malware transforms connected devices, like baby monitors and doorbells, into an army that hackers can control remotely. The so-called Mirai botnet can take down websites, servers, and other key assets for days at a time. A major cyber attack in October 2016 is related to Mirai malware. But the threat isn't over. Mutations to the Mirai virus continue even now. What is the Mirai botnet? The Mirai botnet is made of devices capable of connecting to an internet address. Each device reaches out to a central server that directs the attack. Let's break down the pieces of this threat Devices Connected internet of things IoT devices have stripped-down operating systems, and they can connect to the internet. They're often shipped from the factory with preset usernames and passwords owners rarely change. Infection IoT devices have open Telnet ports. Mirai malware developers search for those open ports, and they attempt to log in with 61 username/password combinations often used as defaults. Malware With login complete, the device downloads and implements malware. Botnet All IoT devices with the malware are part of a network or botnet that works collectively on a goal set by hackers. The Mirai botnet's first iteration was a money-making worm created by two owners of a DDoS mitigation company. In essence, they infected targets and then asked owners to pay them for "protection" from the same attack. The idea was sparked by Minecraft. Players log onto a hosted server, and while they're engaged in the virtual world, they make real-world purchases to lengthen their game time. Knocking a hosting server offline could mean losing thousands of dollars. Victims were willing to pay to stay online. But the Mirai botnet developers started widening their attack surface. What started as an idea used to dominate the Minecraft reality became a tool capable of hurting almost everyone. How does Mirai malware work? When an IoT device is infected with Mirai malware, it can launch tiny attacks against a selected victim. But if thousands of IoT devices are infected, the impact is impossible to ignore. An infected IoT device can Access. The device reaches out to a central server for instructions. Then, it begins to ask for access to a specified server over and over again. Reinfect. Turning off the device can mean stopping an attack and the malware. But if the port stays open, the problem returns with new source code. Dominate. Any other malware on the device is removed, so the Mirai malware is the only one running. Hide. IoT owners may notice slight sluggishness and nothing more. Mirai malware was implicated in a cyber attack in October of 2016. The botnet turned to a website for Dun, which offers domain name system services. The company hosted big-name websites, including Wired. When it went down due to overwhelming traffic due to IoT devices, much of the East Coast went down as well. Entire companies shut down for the weekend due to a lack of connectivity. Authorities got involved, and the Mirai botnet developers panicked. In a rush to protect themselves, they released the Mirai source code. The developers hoped that widespread access to the code could shield them. In essence, they could claim that everyone knew the code, and they got it from elsewhere. Unfortunately, releasing the code ensured that these attacks would persist, in some form, forever. Mirai Bot Changes With Time As soon as the source code was released, hackers started tweaking and adjusting and experimenting. The attacks they launched were devastating. In 2017, for example, a new variant allowed developers to infect home routers secured with strong passwords. When experts discovered it, the botnet was included in an estimated 100,000 devices, all ready to go when the developer offered instructions. This is just one example of many. As long as IoT devices remain even slightly insecure, more variants are likely to appear. Why Can’t We Stop the Mirai Botnet? We know how the Mirai malware works, and we understand how the devices can harm us. Eradication seems a reasonable next step, but unfortunately, it's hard to accomplish. The Mirai worm persists due to Low consumer interest. An infected device still works reasonably well, and it doesn't pose a risk to the person who owns it. People don't feel compelled to change anything about items that seem to work. Poor manufacturer compliance. Cost concerns keep most manufacturing companies from investing in security. The more stripped down the device, the lower the price point. No overarching government insight. Some states have laws about IoT security. In California, for example, IoT devices must be shipped with unique passwords, or manufacturers must require users to set a password before they get started. But there are no federal laws or global laws that ensure widespread compliance. Inadequate skills. Some companies offer security patches for their devices. But some people aren't sure how to apply them to their connected devices, and others have no idea that these patches exist. As long as we live in a world filled with connected devices and poor security practices, the Mirai threat is likely to persist. What Can You Do to Stop the Mirai Worm? Mirai malware is stored in device memory. Rebooting your device, by unplugging it and leaving it that way for a few moments, is usually enough to stop an attack in progress and clean your device. But unless you change your device username and password, reinfection is likely. As soon as you reboot, change those settings. Repeat often for the best chance at protection. If you're not sure how to tackle these steps, contact the device manufacturer for help. Don't expect the manufacturer to install firmware updates. Automatic security setting changes can leave your device vulnerable to man-in-the-middle attacks. References Who Is Anna-Senpai, the Mirai Worm Author? January 2017. Krebs on Security. Source Code for IoT Botnet 'Mirai' Released. October 2016. Krebs on Security. What We Know About Friday's Massive East Coast Internet Outage. October 2016. Wired. 100,000-Strong Botnet Built on Router 0-Day Could Strike at Any Time. December 2017. Ars Technica. IoT Manufacturers What You Need to Know About California's IoT Law. January 2020. The National Law Review. Leaked Mirai Malware Boosts IoT Insecurity Threat Level. October 2016. Security Intelligence. What is Mirai? Mirai is malware that infects smart devices that run on ARC processors, turning them into a network of remotely controlled bots or "zombies". This network of bots, called a botnet, is often used to launch DDoS attacks. Malware, short for malicious software, is an umbrella term that includes computer worms, viruses, Trojan horses, rootkits and spyware. In September 2016, the authors of the Mirai malware launched a DDoS attack on the website of a well-known security expert. A week later they released the source code into the world, possibly in an attempt to hide the origins of that attack. This code was quickly replicated by other cybercriminals, and is believed to be behind the massive attack that brought down the domain registration services provider, Dyn, in October 2016. How does Mirai work? Mirai scans the Internet for IoT devices that run on the ARC processor. This processor runs a stripped-down version of the Linux operating system. If the default username-and-password combo is not changed, Mirai is able to log into the device and infect it. IoT, short for Internet of Things, is just a fancy term for smart devices that can connect to the Internet. These devices can be baby monitors, vehicles, network routers, agricultural devices, medical devices, environmental monitoring devices, home appliances, DVRs, CC cameras, headset, or smoke detectors. The Mirai botnet employed a hundred thousand hijacked IoT devices to bring down Dyn. Who were the creators of the Mirai botnet? Twenty-one-year-old Paras Jha and twenty-year-old Josiah White co-founded Protraf Solutions, a company offering mitigation services for DDoS attacks. Theirs was a classic case of racketeering Their business offered DDoS mitigation services to the very organizations their malware attacked. Why does the Mirai malware remain dangerous? The Mirai is mutating. Though its original creators have been caught, their source code lives on. It has given birth to variants such as the Okiru, the Satori, the Masuta and the PureMasuta. The PureMasuta, for example, is able to weaponize the HNAP bug in D-Link devices. The OMG strain, on the other hand, transforms IoT devices into proxies that allow cybercriminals to remain anonymous. There is also the recently discovered - and powerful - botnet, variously nicknamed IoTrooper and Reaper, which is able to compromise IoT devices at a much faster rate than Mirai. The Reaper is able to target a larger number of device makers, and has far greater control over its bots. What are the various botnet models? Centralized botnets If you think of a botnet as a theatrical play, the C&C Command and Control Server, also known as the C2 server is its director. The actors in this play are the various bots that have been compromised by malware infection, and made part of the botnet. When the malware infects a device, the bot send out timed signals to inform the C&C that it now exists. This connection session is kept open till the C&C is ready to command the bot to do its bidding, which can include sending out spam, password cracking, DDoS attacks, etc. In a centralized botnet, the C&C is able to convey commands directly to the bots. However, the C&C is also a single point of failure If taken down, the botnet becomes ineffective. Tiered C&Cs Botnet control may be organized in multiple tiers, with multiple C&Cs. Groups of dedicated servers may be designated for a specific purpose, for example, to organize the bots into subgroups, to deliver designated content, and so on. This makes the botnet harder to take down. Decentralized botnets Peer-to-peer P2P botnets are the next generation of botnets. Rather than communicate with a centralized server, P2P bots act as both a command server, and a client which receives commands. This avoids the single point of failure problem inherent to centralized botnets. Because P2P botnets operate without a C&C, they are harder to shut down. and Stormnet are examples of malware behind P2P botnets. How does malware turn IoT devices into bots or zombies? In general, email phishing is a demonstrably effective way of infecting the computer - the victim is tricked into either clicking a link that points to a malicious website, or downloading infected attachment. Many times the malicious code is written in such a way that common antivirus software is not able to detect it. In the case of Mirai, the user doesn’t need to do much beyond leaving the default username and password on a newly installed device unchanged. What is the connection between Mirai and click fraud? Pay-per-click PPC, also known as cost-per-click CPC, is a form of online advertising in which a company pays a website to host their advertisement. Payment depends on how many of that site’s visitors clicked on that ad. When CPC data is fraudulently manipulated, it is known as click fraud. This can be done by having people manually click on the ad, by use of automated software, or with bots. Through this process, fraudulent profits can be generated for the website at the expense of the company placing those ads. The original authors of Mirai were convicted for leasing their botnet out for DDoS attacks and click fraud. Why are botnets dangerous? Botnets have the potential to impact virtually every aspect of a person’s life, whether or not they use IoT devices, or even the Internet. Botnets can Attack ISPs, sometimes resulting in denial-of-service to legitimate traffic Send spam email Launch DDoS attacks and bring down websites and APIs Perform click fraud Solve weak CAPTCHA challenges on websites in order to imitate human behavior during logins Steal credit card information Hold companies to ransom with threats of DDoS attacks Why is botnet proliferation so hard to contain? There are many reasons why it is so difficult to stop the proliferation of botnets IoT device owners There is no cost or interruption in service, so there is no incentive to secure the smart device. Infected systems may be cleaned out with a reboot, but since scanning for potential bots happens at a constant rate, it’s possible for them to be reinfected within minutes of the reboot. This means users have to change the default password immediately after reboot. Or they must prevent the device from accessing the Internet until they can reset the firmware, and change the password offline. Most device owners have neither the know-how, nor the motivation to do so. ISPs The increased traffic on their network from the infected device typically does not compare to the traffic that media streaming generates, so there is not much incentive to care. Device manufacturers There is little incentive for device manufacturers to invest in the security of low-cost devices. Holding them liable for attacks might be one way of forcing change, though this might not work in regions with lax enforcement. Ignoring device security comes at great peril Mirai, for example, is able to disable anti-virus software, which makes detection a challenge. Magnitude With over a billion-and-a-half ARC-processor-based devices flooding the market each year, the sheer number of devices that can be conscripted into powerful botnets means that these malware variants have grown in possible impact. Simplicity Ready-to-go botnet kits obviate the need for tech savvy. For $ a botnet may be leased for an entire month. Refer to What is a DDoS Booter/Stresser? for more details. Global IoT Security Standards There is no global entity, or consensus, to define and enforce IoT security standards. While security patches are available for some devices, users might not have the skill, or the incentive, to update. Many manufacturers of low-end devices don’t offer any kind of maintenance at all. For ones that do, it is often not long term. There is also no way to decommission devices once the updates are no longer maintained, making them indefinitely unsecure. Global Law Enforcement The difficulty in tracking down and prosecuting botnet creators makes the containment of botnet proliferation difficult; There is no global Interpol-equivalent International Criminal Police Organization for cybercrime, with corresponding investigative skills. Law enforcement across the globe is commonly not been able to keep up with cybercriminals when it comes to latest technology. Many botnets now employ a DNS technique called Fast Flux in order to hide the domains they use to download malware, or to host phishing sites. This makes them extremely hard to track, and take down. Does botnet infection degrade performance for IoT devices? It might. Every once in a while, infected devices might perform sluggishly, but they mostly work as intended. Owners have no great motivation to find ways to clear out the infection. Addendum A legislation on the desk of California governor, Jerry Brown, requires that IoT devices have reasonable security features “appropriate to the nature and function of the device.” This would come into effect in January 2020. Why this legislation is so important? The lucrative California market makes it impossible for companies to ignore. If they want to sell in California, they will need to improve security in their devices. This will benefit all states.

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