Wednesday, August 08, 2018

That XKCD on voting machine software is wrong

The latest XKCD comic on voting machine software is wrong, profoundly so. It's the sort of thing that appeals to our prejudices, but mistakes the details.

Tuesday, August 07, 2018

What the Caesars (@DefCon) WiFi situation looks like

So I took a survey of WiFi at Caesar's Palace and thought I'd write up some results.

Friday, July 27, 2018

Some changes in how libpcap works you should know

I thought I'd document the solution to this problem I had.

The API libpcap is the standard cross-platform way of sniffing packets off the network. It works on Windows (winpcap), macOS, and all the Unixes. It's better than simply opening a "raw socket" on Unix platforms because it takes advantage of higher performance capabilities of the system, including specialized sniffing hardware.

Thursday, July 12, 2018

Your IoT security concerns are stupid

Lots of government people are focused on IoT security, such as this bill or this recent effort. They are usually wrong. It's a typical cybersecurity policy effort which knows the answer without paying attention to the question. Government efforts focus on vulns and patching, ignoring more important issues.

Wednesday, June 27, 2018

Lessons from nPetya one year later

This is the one year anniversary of NotPetya. It was probably the most expensive single hacker attack in history (so far), with FedEx estimating it cost them $300 million. Shipping giant Maersk and drug giant Merck suffered losses on a similar scale. Many are discussing lessons we should learn from this, but they are the wrong lessons.

Sunday, June 24, 2018

SMB version detection in masscan

My Internet-scale port scanner, masscan, supports "banner checking", grabbing basic information from a service after it connects to a port. It's less comprehensive than nmap's version and scripting checks, but it's better than just recording which ports are open.

I recently extended this banner checking to include SMB. It's a complicated protocol so requires a lot more work than just grabbing text banners like you see on FTP. Implementing this, I've found that nmap and smbclient often fail to get version information. They seem focused on getting the information from a standard location in SMBv1 packets, which gives a text string indicating version. There's another place you get get it, from the NTLMSSP pluggable authentication chunks, which gives version numbers in the form of major version, minor version. and build number. Sometimes the SMBv1 information is missing, either because newer Windows version disable SMBv1 by default (supporting only SMBv2) or because they've disabled null/anonymous sessions. They still give NTLMSSP version info, though.

Sunday, June 17, 2018

Notes on "The President is Missing"

Former president Bill Clinton has contributed to a cyberthriller "The President is Missing", the plot of which is that the president stops a cybervirus from destroying the country. This is scary, because people in Washington D.C. are going to read this book, believe the hacking portrayed has some basis in reality, and base policy on it. This "news analysis" piece in the New York Times is a good example, coming up with policy recommendations based on fictional cliches rather than a reality of what hackers do.