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PyPI: Python packets steal AWS keys from users

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Re: PyPI: Python packets steal AWS keys from users

#21

Post by ed25519FUUU »

cromd wrote: post #16
ed25519FUUU wrote: post #11

Remember that AWS credentials are easy to lock down. At the very least you could add an ACL to only let them be used on your AWS instances. Then you can set up alerts if someone attempts to use them outside.

But wouldn’t any host running the malicious package be vulnerable to having creds stolen from that host? Maybe I don’t know which “ACL” tech you’re referencing. You can limit where credentials are used from, and not just something like where an S3 bucket is read from? (For example)

You can set a permission that says “these credentials can only be used on an aws instance owned by this account”

Even if the creds are stolen they’d need access to an instance in your account to use them. Also you can be alerted if someone attempts to use them anywhere else.

Re: PyPI: Python packets steal AWS keys from users

#22

Post by rurp »

qbasic_forever wrote: post #6
selcuka wrote: post #4

I believe this is something that automated code parsing (a la Github Copilot) could really shine. Those tools are able to explain what a block of code does, so it should be possible to catch many types of malware hidden in source code.

If a human can't figure it out than an AI trained on human behavior (or more specifically, trained on comments left next to code) can't figure it out either. It's not like malware authors annotate their code with nice "here's where I exfiltrate all the user's secret data" comments.

A focused human will currently do better than automated tools, but actually getting a human to focus on this sort of thing is rare. Most projects I'm familiar with use a multitude of dependencies and only do cursory verification of changes at best.

An automated tool to check all depency changes for suspicious code and flag that to a human could be valuable. Whether or not that could be done in a way where wading through the false positives is worth it, I'm not sure, but it's a reasonable idea.

Re: PyPI: Python packets steal AWS keys from users

#23

Post by ElectricalUnion »

dapids wrote: post #17
jart wrote: post #10

Earlier quoted context omitted.

That's not going to stop people from trying though. If people keep abusing the package managers like this, then publishing open source code is at risk of ending up like distributing binaries on Windows, where you need to fight dozens of virus scanners arbitrarily blocking your code for no apparent reason. Imagine opening a tab in VSCode only to see a popup warning saying it might be harmful, even though you just wrot…

That's exactly was vscode does for me.

That is different, vscode finally realized most people don't want stuxnet-class implicit autorun behaviour from random files and folders in your system.

Re: PyPI: Python packets steal AWS keys from users

#24

Post by karxxm »

jb_s wrote: post #20
ashishbijlani wrote: post #9

I've been building tooling to mitigate supply chain attacks like these. Packj [1] analyzes Python/NPM packages for risky code and attributes such as Network/File permissions, expired email domains, etc. Auditing hundreds of direct/transitive dependencies manually is impractical, but Packj can quickly point out access to sensitive files (e.g., SSH keys), spawning shell, data exfiltration, etc. We found a bunch of mali…

Is it easy to find a list of packages that have been pulled from python/npm in the past? Would be interesting to train some models against it

What would the input to such a model be? The malicious code snippets? Or do you want to classify packages according to other meta data?

Re: PyPI: Python packets steal AWS keys from users

#25

Post by jhugo »

devonkim wrote: post #13
323 wrote: post #8

Earlier quoted context omitted.

This is the kind of stuff that antiviruses did for ages, from signature, code simulation to heuristics. They have a lot of expertise in this, it feels like they could branch out in finding malware in source code, instead of in binaries.

Source code has issues with obfuscation methodologies that can defeat a lot of techniques. It’s why companies are trying to build more analysis down into the kernel such as via EBPF. For example, concatenating a series of strings and characters that wind up reading from .AWS/credentials in the end is surprisingly tough to catch based upon simple pattern recognition alone, especially if it’s done in a subtle way such…

Right, code analysis to try to detect places where it reads from ~/.aws/credentials is never going to be reliable. The correct approach is not to run untrusted code in an environment where it can read your AWS credentials.

Re: PyPI: Python packets steal AWS keys from users

#26

Post by jhugo »

ed25519FUUU wrote: post #21
cromd wrote: post #16

Earlier quoted context omitted.

But wouldn’t any host running the malicious package be vulnerable to having creds stolen from that host? Maybe I don’t know which “ACL” tech you’re referencing. You can limit where credentials are used from, and not just something like where an S3 bucket is read from? (For example)

You can set a permission that says “these credentials can only be used on an aws instance owned by this account” Even if the creds are stolen they’d need access to an instance in your account to use them. Also you can be alerted if someone attempts to use them anywhere else.

There are very few situations where it even makes sense to have static credentials on an AWS instance any more. "Ambient" short-lived credentials from the instance profile and assumed roles are much safer.

Re: PyPI: Python packets steal AWS keys from users

#27

Post by jhugo »

ashishbijlani wrote: post #9

I've been building tooling to mitigate supply chain attacks like these. Packj [1] analyzes Python/NPM packages for risky code and attributes such as Network/File permissions, expired email domains, etc. Auditing hundreds of direct/transitive dependencies manually is impractical, but Packj can quickly point out access to sensitive files (e.g., SSH keys), spawning shell, data exfiltration, etc. We found a bunch of mali…

Does this work at the system call level, where it would detect e.g. any attempt to open ~/.aws/credentials, or does it rely on heuristic analysis of the code itself, which will always be able to be "coded around" by the malware authors?

The correct approach would seem to be to not run untrusted code in an environment where it can read your AWS credentials.

Re: PyPI: Python packets steal AWS keys from users

#28

Post by lovelearning »

In Linux, is there a secure, but also convenient and user-friendly, way to prevent processes from having the same default level of access to the filesystem as the human user?

I like Android's system of per-app uid/gid. But AFAIK it's not implemented by any mainstream Linux kernel or distro.

There's AppArmor, but the last time I tried it, I came away with the opinion that it's not very convenient or user-friendly. Perhaps some kind of friendlier CLI or GUI frontend may help.

I'm assuming SELinux can achieve this but I don't have first-hand experience with it and from what I've read online, it seems to be less user-friendly than even AppArmor.

Any other approach you know about? Do secure distros like Qubes OS or Tails implement this systematically?

Re: PyPI: Python packets steal AWS keys from users

#29

Post by paskozdilar »

lovelearning wrote: post #28

In Linux, is there a secure, but also convenient and user-friendly, way to prevent processes from having the same default level of access to the filesystem as the human user? I like Android's system of per-app uid/gid. But AFAIK it's not implemented by any mainstream Linux kernel or distro. There's AppArmor, but the last time I tried it, I came away with the opinion that it's not very convenient or user-friendly. Per…

Containerization is what you want. There are many containerization tools for Linux, Docker being the most popular, and systemd-nspawn being the most Linuxy, but a bit unknown.

Re: PyPI: Python packets steal AWS keys from users

#30

Post by jb_s »

karxxm wrote: post #24
jb_s wrote: post #20

Earlier quoted context omitted.

Is it easy to find a list of packages that have been pulled from python/npm in the past? Would be interesting to train some models against it

What would the input to such a model be? The malicious code snippets? Or do you want to classify packages according to other meta data?

Yeah. I was wondering how easy it would be to classify using a language model/models. ALthough I don't know how it'd work with binary blobs, multiple languages, etc.

I think certain things would be picked up pretty easily e.g. obfuscated code would be a pretty loud feature, but subtle stuff might be undetected and generally I can't see the model being super accurate.

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