-: What we see so far is some scary stuff. 2 2
We can create a backdoor 3 3
that is not detectable by any antivirus. 4 4
And then we can deliver it in ways 5 5
that the target person will not even need to interact 6 6
or they'll be fooled into running the file 7 7
because they're already downloading a file 8 8
and expecting an executable. 9 9
So on today's video, we're going to have a look 10 10
on how you can prevent that from happening to you. 11 11
The first thing, make sure you're not 12 12
being man in the middle. 13 13
So, this is huge because if you're being man in the middle, 14 14
chances are you're gonna get hacked, 15 15
cause we seen in the network section, 16 16
how easy it is to hack someone, 17 17
if you're the man in the middle. 18 18
So, use a tool like xarp or use static ARP tables, 19 19
don't use networks that you don't know or don't trust. 20 20
This way you can kinda increase 21 21
your confidence into your network 22 22
and into the fact that you're not being man in the middle. 23 23
Another security precaution is always make sure you 24 24
use an https, so even on download pages. 25 25
On the download link itself, 26 26
make sure it's https link, it's not a http. 27 27
If it's a https then we won't be able to hijack it 28 28
and backdoor it on the fly. 29 29
The updates is the same, if the updates are coming from 30 30
a https website, then we won't be able to hijack them 31 31
and make fake updates. 32 32
Another tool that could be pretty useful 33 33
is the tool called winMD5. 34 34
Now, every file that is created has a signature. 35 35
So you can generate a signature for every 36 36
for any file. 37 37
And usually when you download the program, 38 38
the website that allow you to download that program 39 39
will also give you a signature, 40 40
or a checksum of that file. 41 41
So, if the file gets modified, such as the way we did 42 42
in back door proxy, so if it gets modified on the way 43 43
the MD5 checksum 44 44
will change as well 45 45
because its calculated from the file 46 46
and it's a one way function. 47 47
So, it can't actually be decrypted. 48 48
So, if anybody modifies the file 49 49
as it's being downloaded or as it's being delivered to you 50 50
the MD5 checksum will change, and this way you'll be, 51 51
you'll know that someone tampered with this file 52 52
and this file is not the original. 53 53
Original file that you're supposed to receive. 54 54
This works into many cases into many scenarios 55 55
and it's a very important concept 56 56
that you need to know. 57 57
So, using the tool is very simple, 58 58
now there is tools for Linux, 59 59
and for Windows to do that 60 60
you can digitally just download the tool and run it. 61 61
And once you download the tool, you can go on the browse, 62 62
it doesn't need to be installed, 63 63
and when you go on the browse, it'll allow you to 64 64
select a file, and once you do that, 65 65
then it'll give you the signature of that file. 66 66
So I'm actually gonna select the download file 67 67
for the tool itself. 68 68
And, if we compare the signature 69 69
with the signature that they're giving us here, 70 70
you'll see that it's identical. 71 71
Which means the tool has not been modified 72 72
as it was downloaded from the website. 73 73
If you do the same, with any file that you download, 74 74
then you'll know that the file has not been modified 75 75
and therefore it hasn't been backdoored. 76 76
So if there's a file in the backdoor, 77 77
then the backdoor existed on the website 78 78
where you downloaded it from. 79 79
So the website itself was serving you a backdoor.