Interesting findings within a VPN app
Interesting findings within a VPN app
edit: please see comments for more informed insights.
I am currently investigating and reverse engineering free VPNs for a master thesis, and just came across something I thought I'd share. VPN in this case is 1clickvpn.net, not .com!
I'm sharing this as a warning as to never use free vpns! They are most often the opposite of what they promise to be. (by free I do not mean the free versions of premium services). But either way; be careful about your VPN choice, as they have access to a lot of sensitive data. I'm sure most peeps here know of this already, but next time you hear someone using a free vpn, let them know...
This first image/code was sitting inside a file called NetworkModule, with some hella weird external links.
- addrDOTcx, seems to have been linked to malware? Comes up flagged as malicious a few times on VirusTotal.
- freevpnDOTzone, seems to be another free possible malicious VPN service, might investigate this one later.
- bigbrolookDOTcom, seems to longer be a registered domain. But wtf? Was this VPN service linked to p*rn??
IMAGE HERE; Don't visit these links unless you know what you're doing.
Furthermore, there is this interesting find; Now I am no expert coder, frankly quite the amateur. But does the below code really mean what I think it does? Seems like it could be creating a fake connection?. This is more-less normal behaviour it seems, considering it is a local address it is probably used for testing purposes or making the app not crash if a connection cant be established.
Is used once here;
Stay safe 🌻
Probably not. It looks like it's setting the fake address before reading the tunnel parameters, where the real address is stored. Probably a kludge in case the connection address is undefined so the program doesn't crash. So check whether the address is included there.
Also check the function that establishes the connection. 10.1.1.1 is not a public subnet, so unless there is a VPN device listening at the local address, the tunnel should fail to establish and throw an error, triggering the exception clause in that code. Again, you'll want to confirm that in the code.
That seems to be the case, probably a killswitch-type feature, ensuring the VPN is working. Additionally, addr[.]cx is a free GeoIP lookup service, and I assume bigbrolook (OP - Big Brother is a term for a surveillance state, the porn definition is only used for 5-10 years) is/was another one. You can confirm with waybackmachine.
Seems to be an amateur free VPN using free infrastructure. Most of the time the free VPNs that turn their users machines into a proxy or do other dirty things will be obfuscated and require at least a bit of reverse engineering, not just opening a debugger and peeking.
Not trying to cast shade here, but isn't a master's thesis after you know a subject incredibly well, and aren't you supposed to look at things no one has looked at before? In case you're not in tech and this is a master's for another subject, this has been done.
Thanks for helping out! Totally should have thought of waybackmachine earlier.
Yes, a lot of these free VPNs seems to be baked with trackers too, and often built on the same infrastructure too.
Can't talk for all masters across all Uni's here, but at least in my country there is no strict requirement that it has to be something no one has ever looked at before, but it does need to be lesser known. While there is a lot of general research on VPNs - mostly the premium ones. There isn't a lot of peer-reviewed research on the free ones, at least not enough - as I had this topic approved by my Uni. Also, the prior research clearly showed that this is a growing problem, at those studies were back from 2016 and 2021. I therefore saw reason to further investigate the state of the free VPN landscape now again in 2024.
It might be for a school in the USA.
BigBroLookDOTcom could be a reference to Orwell's 1948, rather than porn.
1984, not 1948, in case anyone goes looking for the reference
That’s pretty fucking funny “big brother” was associated with porn rather than privacy.
Ah indeed, good find!
Keep in mind the client doesn't have to do anything malicious, since it's their encryption - they could easily examine your traffic while it's on their infrastructure.
Third party VPN like this requires a high degree of trust.
I believe it is easier to pull a man in the middle attack from the client
Yeah! This VPN for instance too has their own proprietary protocol too...
All this really demonstrates is the dangers of drawing conclusions when you don't really have the skills to properly assess the information presented to you.
I have not drawn any conclusions, nor will this be a part of the thesis directly. I am simply looking at the code for extra insights and learning. I wanted to share what I found because I am curious and want to learn. I'm open to constructive feedback, and by all means correct me - im just here to learn.
The addAddress call may just be configuring the local side of the VPN. It's hard to know without looking at the rest of the code.
The general workflow when establishing a VPN connection is:- open a socket to the destination VPN service (ProtonVPN, or whatever suspect service).
- configure parameters such as DNS, split tunneling, and which networks to route over the VPN (generally everything from your local system, except the VPN connection itself).
- update the local routing so traffic starts flowing over the VPN.
addAddress may just be part of the configuration. A very cursory search suggests that OpenVPN may be being used as the underlying VPN implementation framework (not uncommon).
Why are you protecting them? Drop the fucking names lol. I literally do not understand.
1clickvpn.net, have edited the post.
\ (•◡•) / thanks yo
What is sad is that users would not care even when explained why "Fast Free VPN" from Play Store should not be used. It allows them to go to the blocked sites? Then it doesn't matter what else happens. It is very much understandable that people wouldn't want to pay, especially with current restrictions. If I didn't find a way to pay for my VPS, I would have rather gone for a charity-ran VPN or extension.
This is not a good post unless you specify what VPN you’re talking about.
The local IP listed is probably the IP for all clients. You can do some magic with routing on the server side.
Yeah, I think thats also creating a fake connection.
I'd be happy to share more of the code if someone is curious and knows a bit more of Java than I do 😅