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Brute.Fail: Watch brute force attacks fail in real time

brute.fail

231–240 of 268 posts

Re: Brute.Fail: Watch brute force attacks fail in real time

#231
post #27

Earlier quoted context omitted.

I was actually thinking about that: OT1H, fail2ban would really clean up the list, so it's not monopolized by the one joker, but OTOH given sufficient spans of time it would make the output go quiet, which for this specific case defeats the purpose I actually much prefer the projects that give the caller a fake shell, and watch what they type after "breaking in." It'd be the Kitboga of ssh attacks :-D

> give the caller a fake shell, and watch what they type after "breaking in." Oh YES! Do it, please! We could learn a lot!

I believe one of ISC dshield's related projects can do this.

Re: Brute.Fail: Watch brute force attacks fail in real time

#232
post #19

Earlier quoted context omitted.

And since they don't get called out, they won't get an idea. Unless the infection is retargeted against themselves.

I also scan the internet quite a bit. Trust me, they (or the ISP rather) are getting a few emails an hour.

> few emails an hour

Been there, done that. Most isps and providers don't respond or act on abuse complaints anymore.

Re: Brute.Fail: Watch brute force attacks fail in real time

#233

Earlier quoted context omitted.

This is fine, though. "Security through obscurity is not security" but moving your SSH port to something not 22 will utterly eliminate brute force attacks. It's too much bother to go find it, and the bozos will just move on to the next machine with port 22 open.

That's still not really security but just a nuisance mitigation IMO :)

Nuisance mitigations are part of security too! Fewer irrelevant notifications makes it more likely you’ll notice when something really is a problem.

It’s like how an adversary might launch a DDoS attack at the same time as they exploit a SQL injection vulnerability to exfiltrate credit card information. Filling up logs and alerts overwhelms the blue team and makes it harder to notice the quieter, but more dangerous attack.

Re: Brute.Fail: Watch brute force attacks fail in real time

#234
post #25

Its just stupid at this point. You can put up a wordpress site with 5 daily visitors, and you'll still get thousands of SSH / xmlrpc hits per day.

The range of IPV4 address's is small enough that a single server can scan it, in a single day.

So I guess the problem isn't going away.

Re: Brute.Fail: Watch brute force attacks fail in real time

#235
post #104

Earlier quoted context omitted.

I do. For some reason ssh keys became the group-think security advice to repeat ad nauseam. I often find people have only considered this very shallowly, and their reasoning is just "But OMG, entropy lolz" without actually seriously considering the available entropy and likely attack vectors and failure. Why? The benefits are largely theoretical if you choose sufficiently strong randomly generated passphrases, with s…

All of your items are just "i'm doing this wrong" combined with not understanding how keys even work. Your private keys shouldn't even be accessible to you, they should be on a secure enclave like a yubikey, and you should forward the token along the chains. No risks, and basically painless, especially if you switch to certs so you don't even have to know the public keys ahead of time on the servers, just all trust t…

GP is deeply concerned about getting locked out, and your solution is to use a secure enclave?

Re: Brute.Fail: Watch brute force attacks fail in real time

#236

Earlier quoted context omitted.

This is fine, though. "Security through obscurity is not security" but moving your SSH port to something not 22 will utterly eliminate brute force attacks. It's too much bother to go find it, and the bozos will just move on to the next machine with port 22 open.

That's still not really security but just a nuisance mitigation IMO :)

Security through obscurity actually is security, and is perfectly valid to use with a defense in depth strategy. The problem is when obscurity is the only defense.

Re: Brute.Fail: Watch brute force attacks fail in real time

#237

So funny story, for a while I worked on a 'reverse' exploit. Which is to say morphing the response from ssh to the client with large malformed packets. The idea was to crash the client making the request. In my case I found these attacks would have like 6 to 10 attempts from the same source address. By time stamping the requests, I could evaluate if the next attack from the same address came more quickly or more slow…

Details!

Seriously this is both hilarious and intriguing and deserves a long form blog post or something.

Re: Brute.Fail: Watch brute force attacks fail in real time

#238
post #207

Earlier quoted context omitted.

> A nice aspect of wireguard is that it's "steath", meaning that it does not respond to unauthenticated connections at all, so there is no way to probe and scan for wireguard listeners at all. I did not know this. That’s really cool. Is it done over a stateless protocol like UDP, or is a TCP connection opened first? Ie. is it impossible to see if there’s even a server there at all, or is it first revealed that there’…

It's over UDP, you can't probe for wireguard AFAIK

depends on your firewall, lots of setups give you an ICMP port unreachable in response to probing closed udp ports so you can often tell a wireguard host if the default port doesn't (in practice)

Re: Brute.Fail: Watch brute force attacks fail in real time

#239
post #138

So funny story, for a while I worked on a 'reverse' exploit. Which is to say morphing the response from ssh to the client with large malformed packets. The idea was to crash the client making the request. In my case I found these attacks would have like 6 to 10 attempts from the same source address. By time stamping the requests, I could evaluate if the next attack from the same address came more quickly or more slow…

Another fun one is sending a redirect to a gzip bomb or extremely large file (i.e. speedtest download file) for when certain non-existant URLs are requested, i.e. /wp-login.php on a non-wordpress site.

Is it legal to host a gzip bomb? Seems like a malicious file to serve up…

Re: Brute.Fail: Watch brute force attacks fail in real time

#240
post #239
post #138

Earlier quoted context omitted.

Another fun one is sending a redirect to a gzip bomb or extremely large file (i.e. speedtest download file) for when certain non-existant URLs are requested, i.e. /wp-login.php on a non-wordpress site.

Is it legal to host a gzip bomb? Seems like a malicious file to serve up…

It can cause your site to end up on Google's safe Browsing black list which can be a death sentence for a business. Google has automated process for identifying malware and black list such websites. Almost all browsers use this list to warn users. This is why it is also dangerous to host anonymous uploaded files even for a short time. https://news.ycombinator.com/item?id=25802366
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