Category Archives: Security

Configuring Fail2Ban for ProFTPd

Suppose Fail2Ban is already installed, if not, then see my article – Installing and Configuring Fail2ban.

In Fail2Ban by default, there are already filters for ProFTPd and it knows that the log file is located at /var/log/proftpd/proftpd.log, so it’s enough to create the file:

sudo nano /etc/fail2ban/jail.d/proftpd.local

And enter the data below, thereby activating the check of the log file /var/log/proftpd/proftpd.log:

[proftpd]
enabled = true
bantime = 86400

Restart Fail2Ban to apply the changes:

sudo service fail2ban restart

You can check the status:

sudo fail2ban-client status proftpd

Installing Nessus on Linux

Nessus – vulnerability scanner in Linux.

Go to the official website http://www.tenable.com/products/nessus/select-your-operating-system and download Nessus for the operating system that you have installed.

Switch to the root user:
su

Run the installation of the downloaded file, for example:

dpkg -i Nessus-7.0.2-debian6_amd64.deb

Run Nessus:

/etc/init.d/nessusd start

After that, you can open Nessus in the browser by clicking https://IP:8834/

For further work, you need to register with https://www.tenable.com/products/nessus/activation-code.

How to make a bootable USB flash drive with CAINE

To make a bootable USB flash drive with CAINE, perform several actions:

1) Download the image CAINE from the official site www.caine-live.net

2) Download Universal USB Installer http://www.pendrivelinux.com/universal-usb-installer-easy-as-1-2-3/

3) We connect the USB flash drive to the computer and run the Universal USB Installer. In it, we agree with the license agreement by clicking “I Agree“, in the second window where “Step 1:” choose “CAINE Linux“, where “Step 2” click “Browse” and point to the downloaded image of CAINE (for example, caine9.0.iso). In “Step 3:” select the letter of the flash drive, tick the “Format” (this will re-partition the file system table and erase all the data on the USB flash drive).

4) Click “Create” and wait for the process to complete.

Using netwox

I will give examples of using netwox and describe them.
I described the netwox installation in this article – Установка netwox

Example of a standard startup:

sudo netwox

netwox has quite a lot of functions, you can see them by pressing after starting the number 3 and Enter.

Network configuration display:

sudo netwox 1

Display debugging information:

sudo netwox 2

Display information about the IP address or host name:

sudo netwox 3 example.com

Displaying information about the MAC address:

sudo netwox 4 -e 00:15:5D:38:01:08

Obtaining MAC addresses from the IP list:

sudo netwox 5 -i 192.168.1.0/24

Display information that will be used to reach the specified IP address:

sudo netwox 6 192.168.24.254

Sniffer, displaying the transmitted packets on the screen:

sudo netwox 7

Sniffer, displaying only the list of open ports that were used in the captured packets:

sudo netwox 8

Sniffer, mapping of MAC and IP addresses:

sudo netwox 9

An example of capturing packets and displaying brief statistics (the number of packets counted, the size of packages, the percentage of the number of packets (c%), the percentage of the size (s%)):

netwox 10 -d eth0

Convert a digit to an encrypted one:

sudo netwox 21 -n number

Converting a string to an encrypted string (sha256, md5, etc.):

sudo netwox 22 -d text

Show ASCII table:

sudo netwox 23

Check the security of the directory:

sudo netwox 25 /tmp/

Example of ICMP PING:

sudo netwox 49 -i 192.168.24.253

Example of ARP PING:

sudo netwox 55 -i 192.168.24.253

Example ICMP route tracing:

sudo netwox 57 -i examle.com

Example of TCP route tracing:

sudo netwox 59 -i examle.com

Example UDP route tracing:

sudo netwox 61 -i examle.com

Example of port scanning:

sudo netwox 67 -i 192.168.24.254 -p 1-1000

ICMP scanning for availability:

sudo netwox 65 -i 192.168.1.0/24

TCP port access scan:

sudo netwox 67 -i 192.168.1.0/24 -p 80

UDP port access scan:

sudo netwox 69 -i 192.168.1.0/24 -p 80

ARP scanning:

sudo netwox 71 -i 192.168.1.0/24

Flood random fragments:

sudo netwox 74 -i 192.168.24.254

Filling the table of MAC-addresses of the switch by sending a flood:

sudo netwox 75

Synflood:

sudo netwox 76 -i 192.168.24.254 -p 80

etc.

Configure Firefox for anonymity

To get started, type the following in the address bar of the Firefox browser:

about:config

Below I will describe what settings transmit information about the user, for faster search, you can copy and paste the parameter into the search bar.

Google Safe Browsing (the parameter includes the transmission of information about the sites visited by the user on Google and prevents visits to sites with malicious software):

browser.safebrowsing.enabled
browser.safebrowsing.downloads.enabled
browser.safebrowsing.malware.enabled

Sending stability and performance reports to Firefox:

datareporting.healthreport.service.enabled
datareporting.healthreport.uploadEnabled

Usage statistics:

toolkit.telemetry.enabled

The parameter transmits the real IP address even if a VPN connection or TOR is used:

media.peerconnection.enabled

Enabling integration with the Pocket service:

browser.pocket.enabled

Using geolocation:

geo.enabled

Firefox connects to third-party servers without permission:

loop.enabled

Saving typed text in the search, for further tips:

browser.search.suggest.enabled

Enabling locks to track user information:

privacy.trackingprotection.enabled

Some information about the virus encryptor Trojan.Encoder.12544 attacked 06/27/2017

06/27/2017 After lunch, I received a call from one organization and reported that many computers stopped working, but some worked, I understood that Windows auto-update was enabled and all updates were installed, including the critical vulnerability fix that the virus uses – Microsoft Security Bulletin MS17-010 – Critical

On some infected computers, there was the following window (infected MBR area):

On the other side, the disk was checked for errors via CHDISK, as it turned out to be the second stage of the virus – disk encryption using AES-128-CBC algorithms and in this case, an immediate shutdown is necessary to recover the remaining unencrypted data.
Through special utilities, you could see only a few unencrypted data that can be recovered, and the rest can only be returned from backup copies made by system administrators since the decryptor is not available at the moment.
Under the old version of the virus last year, the decryptor was written https://github.com/leo-stone/hack-petya

The mail that was specified for requesting the decryption key was blocked after some time after the virus appeared, even about 45 transactions were received on the wallet.