One of the most mind-blowing presentations at this year's Chaos Communications Congress (28C3) was Ang Cui's Print Me If You Dare, in which he explained how he reverse-engineered the firmware-update process for HPs hundreds of millions of printers. Cui discovered that he could load arbitrary software into any printer by embedding it in a malicious document or by connecting to the printer online. As part of his presentation, he performed two demonstrations: in the first, he sent a document to a printer that contained a malicious version of the OS that caused it to copy the documents it printed and post them to an IP address on the Internet; in the second, he took over a remote printer with a malicious document, caused that printer to scan the LAN for vulnerable PCs, compromise a PC, and turn it into a proxy that gave him access through the firewall (I got shivers).
Cui gave HP a month to issue patches for the vulnerabilities he discovered, and HP now has new firmware available that fixes this (his initial disclosure was misreported in the press as making printers vulnerable to being overheated and turning into "flaming death bombs" -- he showed a lightly singed sheet of paper that represented the closest he could come to this claim). He urges anyone with an HP printer to apply the latest patch, because malware could be crafted to take over your printer and then falsely report that it has accepted the patch while discarding it.
Cui's tale of reverse-engineering is a fantastic look at the craft and practice of exploring security vulnerabilities. Read the rest
Today at the Chaos Computer Congress in Berlin (28C3), Sadia Afroz and Michael Brennan presented a talk called "Deceiving Authorship Detection," about research from Drexel College on "Adversarial Stylometry," the practice of identifying the authors of texts who don't want to be identified, and the process of evading detection. Stylometry has made great and well-publicized advances in recent years (and it made the news with scandals like "Gay Girl in Damascus"), but typically this has been against authors who have not taken active, computer-assisted countermeasures at disguising their distinctive "voice" in prose.
As part of the presentation, the Drexel Team released Anonymouth, a free/open tool that partially automates the process of evading authorship detection. The tool is still a rough alpha, and it requires human intervention to oversee the texts it produces, but it is still an exciting move in adversarial stylometry tools. Accompanying the release are large corpuses of test data of deceptive and non-deceptive texts.
Stylometry has been cited by knowledgeable critics as proof of the pointlessness of the Nym Wars: why argue for the right to be anonymous or pseudonymous on Google Plus or Facebook when stylometry will de-anonymize you anyway? I've been suspect of these critiques because they assume that only de-anonymizers will have access to computer-assisted tools, but as Anonymouth shows, there are many opportunities to use automation tools to improve anonymity.
Stylometry matters in many ways: its state of the art changes the balance of power between trolls and moderators, between dissidents and dictators, between employers and whistleblowers, between astroturfers and commenters, and between spammers and filters. Read the rest