Weak entropy is an industry-wide challenge for network device vendors. We conducted a large scale analysis of RSA keys in about 226 million device certificates from one vendor, covering products that were manufactured over a 12-year time period. By focusing on specific data features of the manufacturing certificates, we tested for common keys and common factors across distinct devices. The scale of our analysis enabled the detection of entropy failures that manifested in the RSA keys of millions of devices. The affected devices included several products not implicated in any prior studies, resulting in the discovery of three new vulnerabilities in actively supported products. The entropy failures were complex, resulting from both low initial entropy and the faulty composition of manufacturing processes. Most affected product families were lower-margin devices past their end-of-support date; higher-end products that used a vendor-sanctioned hardware entropy source did not exhibit these weaknesses. However, our findings warrant more proactive and systematic entropy testing by device vendors.

Spam-based advertising is a business. While it has engendered both widespread antipathy and a multi-billion dollar anti-spam industry, it continues to exist because it fuels a profitable enterprise. We lack, however, a solid understanding of this enterprise's full structure, and thus most anti-Spam interventions focus on only one facet of the overall spam value chain (e.g., spam filtering, URL blacklisting, site takedown).In this paper we present a holistic analysis that quantifies the full set of resources employed to monetize spam email -- including naming, hosting, payment and fulfillment -- using extensive measurements of three months of diverse spam data, broad crawling of naming and hosting infrastructures, and over 100 purchases from spam-advertised sites. We relate these resources to the organizations who administer them and then use this data to characterize the relative prospects for defensive interventions at each link in the spam value chain. In particular, we provide the first strong evidence of payment bottlenecks in the spam value chain, 95% of spam-advertised pharmaceutical, replica and software products are monetized using merchant services from just a handful of banks.

We report on the aftermath of the discovery of a severe vulnerability in the Debian Linux version of OpenSSL. Systems affected by the bug generated predictable random numbers, most importantly public/private keypairs. To study user response to this vulnerability, we collected a novel dataset of daily remote scans of over 50,000 SSL/TLS-enabled Web servers, of which 751 displayed vulnerable certificates. We report three primary results. First, as expected from previous work, we find an extremely slow rate of fixing, with 30% of the hosts vulnerable when we began our survey on day 4 after disclosure still vulnerable almost six months later. However, unlike conventional vulnerabilities, which typically show a short, fast fixing phase, we observe a much flatter curve with fixing extending six months after the announcement. Second, we identify some predictive factors for the rate of upgrading. Third, we find that certificate authorities continued to issue certificates to servers with weak keys long after the vulnerability was disclosed.

The of spam--the probability that an unsolicited e-mail will ultimately elicit a sale--underlies the entire spam value proposition. However, our understanding of this critical behavior is quite limited, and the literature lacks any quantitative study concerning its true value. In this paper we present a methodology for measuring the conversion rate of spam. Using a parasitic infiltration of an existing botnet's infrastructure, we analyze two spam campaigns: one designed to propagate a malware Trojan, the other marketing on-line pharmaceuticals. For nearly a half billion spam e-mails we identify the number that are successfully delivered, the number that pass through popular anti-spam filters, the number that elicit user visits to the advertised sites, and the number of sales and infections produced.