Monday, October 24, 2016

Lamers: the problem with bounties

In my last two posts, I pointed out that the anti-spam technique known as "DKIM" cryptographically verifies emails. This can be used to verify that some of the newsworthy emails are, indeed, correct and haven't been doctored. I offer a 1 btc (one bitcoin, around ~$600 at current exchange rates) bounty if anybody can challenge this assertion.

Unfortunately, bounties attract lamers who think they deserve the bounty. 

This faked email show _undetectable_ addition of cc: field (& other fields) and whitespace in email body; no tricks #PayUpRob @ErrataRob https://t.co/X8oUplx2UL
— ((( Matt Beebe ))) (@VoteBeebe) October 25, 2016

This guy insists he wins the bounty because he can add spaces to the email, and add fields like "Cc:" that DKIM doesn't check. Since DKIM ignores extra spaces and only checks important fields, these changes pass. The guy claims it's "doctored" because technically, he has changed things, even though he hasn't actually changed any of the important things (From, Date, Subject, and body content).

No. This doesn't qualify for the bounty. It doesn't call into question whether the Wikileaks emails say what they appear to say. It's so obvious that people have already contacted me and passed on it, knowing it wouldn't win the bounty. If I'd pay out this bounty for this lameness, one of the 10 people who came up with the idea before this lamer would get this bounty, not him. It'd probably go to this guy:
@ErrataRob super lame i know, but this does pass DKIM sig check in thunderbird. base64 here https://t.co/14EyaBKfNL pic.twitter.com/dG94f5lH8o
— Philip (@_miw) October 22, 2016

Let me get ahead of the lamers and point to more sophisticated stuff that also doesn't count. The following DKIM verified email appears to say that Hillary admitting she eats kittens. This would be newsworthy if true, and a winner of this bounty if indeed it could trick people.
This is in fact also very lame. I mean, it's damn convincing, but only to lamers. You can see my trick by looking at the email on pastebin (http://pastebin.com/wRsnz0Y6) and comparing it to the original (https://wikileaks.org/podesta-emails/emailid/2986).

The trick is that I've added extra From/Subject fields before the DKIM header, so DKIM doesn't see them. DKIM only sees the fields after. It tricks other validation tools, such as this online validator. However, email readers (Thunderbird, Outlook, Apple Mail) see the first headers, and display something that DKIM hasn't checked.

I've taken a screenshot of the raw email to show both From fields:

Since I don't rely upon the "magic" of tools to verify DKIM, but look at the whole package, I'll see the added From/Subject fields. Far from fooling anybody, such modifications will be smoking gun that somebody has attempted illicit modifications. Not just me, mostly anybody viewing the "raw source" that Wikileaks provides would instantly see shenanigans.


The Wikileaks emails can be verified with crypto, using DKIM. Anybody who can doctor an email in such a way that calls this into question, such that they could pass something incriminating through ("I eat kittens"), they win the full bounty. Any good attempts, with something interesting and innovative, wins partial bounty.

Lamers, though, are unwelcome.

BTW, the same is true for bug bounties. Bounties are becoming standard in the infosec industry, whereby companies give people money if they can show ways hackers might hack products. Paying bounties allows companies to fix products before they actually get hacked. Even the U.S. military offers bounties if you can show ways to hack their computers. Lamers are a pox on bug bounty systems -- administrators must spend more time telling lamers to go away than they spend on dealing with real issues. No bounties rules are so tight that lamers can't find a way to subvert the rules without finding anything that matches the intent.



from Lamers: the problem with bounties

No comments:

Post a Comment