Stories with Tag teardown

• Reverse-engineering and analysis of SanDisk High Endurance microSDXC card (2020)

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  Posted: 2025-02-02 10:32:40

  Verbose tl;dr

  The blog post details a teardown and analysis of a SanDisk High Endurance microSDXC card. The author physically de-caps the card to examine the controller and flash memory chips, identifying the controller as a SMI SM2703 and the NAND flash as likely Micron TLC. They then analyze the card's performance using various benchmarking tools, observing consistent write speeds around 30MB/s, significantly lower than the advertised 60MB/s. The author concludes that while the card may provide decent sustained write performance, the marketing claims are inflated and the "high endurance" aspect likely comes from over-provisioning rather than superior hardware. The post also speculates about the internal workings of the pSLC caching mechanism potentially responsible for the consistent write speeds.

  This blog post by "bunnie" delves into a detailed teardown and analysis of a SanDisk High Endurance microSDXC card, specifically the 256GB variant. Motivated by a desire to understand the inner workings of these cards, particularly their longevity claims and performance characteristics, bunnie embarked on a physical and logical dissection of the device.

  The physical teardown began with identifying the controller, a Silicon Motion SM2708, known for its cost-effectiveness and inclusion of wear-leveling and error correction capabilities. Bunnie notes the challenge in accessing the internal components due to the robust epoxy encapsulation, resorting to a combination of acetone soaking, mechanical force, and a hot air gun to carefully expose the die. This revealed a Micron-manufactured NAND flash chip, identified as NW943, indicative of 96-layer 3D TLC NAND. The author emphasizes the complexity and miniaturization of these components, highlighting the intricate layering and sophisticated manufacturing processes involved.

  Beyond the physical analysis, the post proceeds to explore the card's logical structure and performance. Using specialized tools, bunnie examines the card's firmware and internal organization. He describes the concept of "pseudo-SLCs" (pSLC), a technique employed to boost write speeds by treating a portion of the TLC NAND as SLC. This offers higher performance but reduces overall capacity. The investigation further reveals that the card dedicates approximately 4GB to this pSLC region, dynamically managing its usage for optimal write performance.

  The post also analyzes the card's wear-leveling strategies, a crucial aspect of flash memory longevity. Wear-leveling distributes write operations across the entire NAND array to prevent premature wear on specific blocks. Bunnie observes a sophisticated dynamic wear-leveling implementation, evident through monitoring write patterns and observing the even distribution of writes across different blocks. This dynamic approach, as opposed to static wear-leveling, contributes to the card's extended lifespan, particularly important for high-endurance applications like dashcams and security cameras.

  Furthermore, the author examines the card's error correction mechanisms. He emphasizes the importance of robust error correction in flash memory due to the inherent susceptibility of NAND cells to bit flips and other errors. The SanDisk card implements powerful error correction codes (ECC) to ensure data integrity, contributing to its reliability in demanding environments.

  Finally, the post concludes with reflections on the findings. Bunnie expresses admiration for the intricate engineering involved in creating such a compact and robust storage device. The analysis highlights the clever techniques employed, such as pSLC and dynamic wear-leveling, to balance performance, endurance, and cost. The investigation provides valuable insights into the inner workings of modern high-endurance microSD cards and sheds light on the sophisticated technology that enables reliable data storage in a wide range of applications.

  • Reverse Engineering
  • teardown
  • analysis
  • MicroSDXC
  • SanDisk
  • Flash Memory
  • NAND Flash
  • data storage
  • Electronics
  • Hardware
  • High Endurance
  • Memory Card
  • SD Card

  Summary of Comments ( 74 )
  https://news.ycombinator.com/item?id=42907766

  Verbose tl;dr

  Hacker News users discuss the intricacies of the SanDisk High Endurance card and the reverse-engineering process. Several commenters express admiration for the author's deep dive into the card's functionality, particularly the analysis of the wear-leveling algorithm and its pSLC mode. Some discuss the practical implications of the findings, including the limitations of endurance claims and the potential for data recovery even after the card is deemed "dead." One compelling exchange revolves around the trade-offs between endurance and capacity, and whether higher endurance necessitates lower overall storage. Another interesting thread explores the challenges of validating write endurance claims and the lack of standardized testing. A few commenters also share their own experiences with similar cards and offer additional insights into the complexities of flash memory technology.

  The Hacker News post titled "Reverse-engineering and analysis of SanDisk High Endurance microSDXC card (2020)" has generated several comments discussing various aspects of the linked article.

  Some users express appreciation for the in-depth analysis presented in the article. They commend the author's effort in meticulously dissecting the card's hardware and firmware, providing a rare glimpse into the inner workings of such devices. The level of detail, including chip identification and firmware analysis, is highlighted as particularly impressive.

  Several commenters engage in a discussion regarding the wear-leveling strategies employed by flash storage devices. The concept of "over-provisioning" is brought up, with users explaining how manufacturers allocate extra storage capacity that's not accessible to the user, specifically to manage wear leveling and prolong the lifespan of the card. Some discuss the trade-off between endurance and capacity, acknowledging that high-endurance cards often sacrifice some storage space for enhanced longevity. The specific wear-leveling techniques employed by SanDisk, as revealed in the article, are a point of interest, with users speculating on their effectiveness and potential drawbacks.

  The use of p-doped NAND flash memory in the SanDisk card is also a topic of discussion. Users debate the advantages and disadvantages of this technology compared to other types of NAND flash, particularly in the context of endurance and performance.

  One commenter raises the issue of counterfeit memory cards, suggesting that the analysis presented in the article could be helpful in identifying fake or lower-quality cards masquerading as high-endurance products.

  A few users mention the potential security implications of the firmware analysis, noting that vulnerabilities discovered through such reverse-engineering could be exploited for malicious purposes.

  Finally, some comments touch on the broader topic of data recovery and the challenges involved in retrieving data from failed or damaged flash storage devices. The complexity of the firmware and wear-leveling algorithms is cited as a significant obstacle in these scenarios.

• Investigating an “evil” RJ45 dongle

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  Posted: 2025-01-17 20:41:56

  Verbose tl;dr

  A seemingly innocuous USB-C to Ethernet adapter, purchased from Amazon, was found to contain a sophisticated implant capable of malicious activity. This implant included a complete system with a processor, memory, and network connectivity, hidden within the adapter's casing. Upon plugging it in, the adapter established communication with a command-and-control server, potentially enabling remote access, data exfiltration, and other unauthorized actions on the connected computer. The author meticulously documented the hardware and software components of the implant, revealing its advanced capabilities and stealthy design, highlighting the potential security risks of seemingly ordinary devices.

  This blog post details a security researcher's in-depth analysis of a seemingly innocuous USB-to-Ethernet adapter, marketed under various names including "J-CREW JUE135" and suspected of containing malicious functionality. The author, known for their work in network security, begins by outlining the initial suspicion surrounding the device, stemming from reports of unexplained network activity and concerns about its unusually low price. The investigation starts with basic external observation, noting the device's compact size and labeling inconsistencies.

  The author then proceeds with a meticulous hardware teardown, carefully documenting each step with high-quality photographs. This process reveals the surprising presence of a complete, albeit miniature, System-on-a-Chip (SoC), far more complex than what is required for simple USB-to-Ethernet conversion. This unexpected discovery immediately raises red flags, suggesting the device possesses capabilities beyond its advertised function. The SoC is identified as a Microchip LAN7500, which, while not inherently malicious, is powerful enough to run embedded software, opening the possibility of hidden malicious code.

  The subsequent analysis delves into the device's firmware, extracted directly from the flash memory chip on the SoC. This analysis, aided by various reverse engineering tools and techniques, reveals the presence of a complex networking stack, including support for various protocols like DHCP, TCP, and UDP, again exceeding the requirements for basic Ethernet adaptation. Furthermore, the firmware analysis uncovers intriguing code segments indicative of functionalities such as network packet sniffing, data exfiltration, and even the ability to act as a covert network bridge.

  The author meticulously dissects these suspicious code segments, providing a detailed technical explanation of their potential operation and implications. The investigation strongly suggests the dongle is capable of intercepting and potentially modifying network traffic, raising serious security concerns. While the exact purpose and activation mechanism of these malicious functionalities remain somewhat elusive at the conclusion of the post, the author strongly suspects the device is designed for surreptitious network monitoring and data collection, potentially posing a significant threat to users' privacy and security. The post concludes with a call for further investigation and analysis, emphasizing the importance of scrutinizing seemingly benign devices for potential hidden threats. The author also notes the broader implications of this discovery, highlighting the potential for similar malicious hardware to be widely distributed and the challenges of detecting such threats.

  • RJ45
  • dongle
  • Hardware
  • Security
  • networking
  • Electronics
  • implant
  • surveillance
  • Cybersecurity
  • Malware
  • analysis
  • teardown
  • Reverse Engineering
  • Embedded Systems
  • Supply Chain Security

  Summary of Comments ( 149 )
  https://news.ycombinator.com/item?id=42743033

  Verbose tl;dr

  Hacker News users discuss the practicality and implications of the "evil" RJ45 dongle detailed in the article. Some question the dongle's true malicious intent, suggesting it might be a poorly designed device for legitimate (though obscure) networking purposes like hotel internet access. Others express fascination with the hardware hacking and reverse-engineering process. Several commenters discuss the potential security risks of such devices, particularly in corporate environments, and the difficulty of detecting them. There's also debate on the ethics of creating and distributing such hardware, with some arguing that even proof-of-concept devices can be misused. A few users share similar experiences encountering unexpected or unexplained network behavior, highlighting the potential for hidden hardware compromises.

  The Hacker News post titled "Investigating an “evil” RJ45 dongle" (linking to an article on lcamtuf.substack.com) generated a substantial discussion with a variety of comments. Several commenters focused on the security implications of such devices, expressing concerns about the potential for malicious actors to compromise networks through seemingly innocuous hardware. Some questioned the practicality of this specific attack vector, citing the cost and effort involved compared to software-based exploits.

  A recurring theme was the "trust no hardware" sentiment, emphasizing the inherent vulnerability of relying on third-party devices without thorough vetting. Commenters highlighted the difficulty of detecting such compromised hardware, especially given the increasing complexity of modern electronics. Some suggested open-source hardware as a potential solution, allowing for greater transparency and community-based scrutiny.

  Several commenters discussed the technical aspects of the dongle's functionality, including the use of a microcontroller and the potential methods of data exfiltration. There was speculation about the specific purpose of the device, ranging from targeted surveillance to broader network mapping.

  Some commenters drew parallels to other known hardware-based attacks, reinforcing the ongoing need for vigilance in hardware security. Others shared anecdotes of encountering suspicious or malfunctioning hardware, adding a practical dimension to the theoretical discussion. A few commenters offered humorous takes on the situation, injecting levity into the otherwise serious conversation about cybersecurity.

  Several threads delved into the specifics of USB device functionality and the various ways a malicious device could interact with a host system. This included discussion of USB descriptors, firmware updates, and the potential for exploiting vulnerabilities in USB drivers.

  The overall sentiment seemed to be one of cautious concern, acknowledging the potential threat posed by compromised hardware while also recognizing the need for further investigation and analysis. The discussion provided valuable insights into the complex landscape of hardware security and the challenges of protecting against increasingly sophisticated attack vectors. The diverse perspectives offered by the commenters contributed to a rich and informative conversation surrounding the topic of the "evil" RJ45 dongle.