Attack Techniques: Encrypted Archives

Tricking a user into downloading and opening malware is a common attack technique, and defenders have introduced security scanners to many layers of the ecosystem in an attempt to combat the technique: With all this scanning in place, attackers have great incentives to try to prevent their malicious code from detection up until the momentContinue reading “Attack Techniques: Encrypted Archives”

New TLDs: Not Bad, Actually

The Top Level Domain (TLD) is the final label in a fully-qualified domain name: The most common TLD you’ll see is com, but you may be surprised to learn that there are 1479 registered TLDs today. This list can be subdivided into categories: Some TLD owners will rent domain names under the TLD to anyContinue reading “New TLDs: Not Bad, Actually”

Leaky Abstractions

In the late 1990s, the Windows Shell and Internet Explorer teams introduced a bunch of brilliant and intricate designs that allowed extension of the shell and the browser to handle scenarios beyond what those built by Microsoft itself. For instance, Internet Explorer supported the notion of pluggable protocols (“What if some protocol, say, FTPS, becomesContinue reading “Leaky Abstractions”

Compression Context

ZIP is a great format—it’s extremely broadly deployed, relatively simple, and supports a wide variety of use-cases pretty well. ZIP is the underlying format beneath Java (.jar) Archives, Office (docx/xlsx/pptx) files, Fiddler (.saz) Session Archive ZIP files, and many more. Even though some features (Unicode filenames, AES encryption, advanced compression engines) aren’t supported by allContinue reading “Compression Context”

Repairing Corrupt ZIP Files

Fiddler’s default file format is the SAZ Format, which is just a ZIP file with a particular structure (I’ve written a lot about ZIPs). Unfortunately, sometimes users’ SAZ files get corrupted due to failing disks or incomplete downloads, and when this happens, Fiddler can no longer open them. Because Fiddler uses a standard ZIP file,Continue reading “Repairing Corrupt ZIP Files”