📃Everything Linux

📜 In this 🐧 Linux notes repository, I store all of my notes related to the Linux operating system and Unix based apps.

• 📌_Some commands can be outdated._

• ❗_Most of the commands are for Debian-based distributions._

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🌐 Resources 🔗

• DistroWatch.com

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Terminal commands

Linux Kernel version

uname -srm

Linux Distribution

cat /etc/*release

Linux OS Install date

stat -c %w /

stat / | grep "Birth" | sed 's/Birth: //g' | cut -b 2-11
stat / | awk '/Birth: /{print $2}'

Cpu - Ram usage

top
iostatmpstat
vmstat 1 5
mpstat -P ALL 2 4
sar -P ALL 2 3

sudo apt-get install htop
htop

sudo apt-get install nmon
nmon

# Check installed hw RAM memory
sudo dmidecode --type memory

Check Swap usage

cat /proc/swaps
swapon -s
grep Swap /proc/meminfo
free -m

htop

Swap Enable

• To enable swap with btrfs disk run

sudo btrfs filesystem mkswapfile --size 4G /swapfile
sudo swapon /swapfile

Disk - Extend LVM Partition

echo 1>/sys/class/block/sda/device/rescan
sudo cfdisk
# Resize the wanted partition
# sudo lsblk
# sudo vgdisplay -v
# sudo pvresize /dev/<your_sda>
# sudo lvextend -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv
# sudo vgdisplay -v
# sudo resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv
df -h

Hardware Check

inxi -F

ACPI Powerstate

sudo dmesg | grep ACPI | grep supports

🔗 System Sleep States

State:		Suspend-To-Idle
ACPI state:	S0
Label:		"s2idle" ("freeze")

State:		Standby / Power-On Suspend
ACPI State:	S1
Label:		"shallow" ("standby")

State:		Suspend-to-RAM (STR)
ACPI State:	S3
Label:		"deep"

State:		Suspend-to-disk (STD/Hibernation)
ACPI State:	S4
Label:		"disk"

Terminal clean

clear
# or CTRL+L

System off

sudo shutdown now

General update

sudo apt update && sudo apt upgrade -y && sudo apt clean -y && sudo apt autoremove -y
sudo apt dist-upgrade

sudo apt clean && sudo apt autoremove
sudo apt autoclean
sudo apt --purge autoremove

Info:

• apt clean → cleans the packages and install script in /var/cache/apt/archives/ (removes all stored archives in your cache)

• apt autoclean → cleans obsolete deb-packages, less than clean (removes all stored archives in your cache for packages that can not be downloaded anymore (thus packages that are no longer in the repo or that have a newer version in the repo))

• apt autoremove → removes orphaned packages which are not longer needed from the system, but not purges them, use the --purge option together with the command for that.

• apt --purge autoremove → remove config files and (more important as it cleans dead subdirectories from the documentation tree) entries from /usr/share/doc.

Create Aliases

• Ubuntu:

nano ~/.bashrc
# Append the following text with personal commands. O.S. update in this case:

alias updateos='sudo -- sh -c "sudo apt update && sudo apt -y upgrade && sudo apt -y autoremove"'

# Load changes:
source ~/.bashrc

# List all aliases:
alias

• Kali Linux:

nano ~/.zshrc
# Append the following text with personal commands. O.S. update in this case:

alias updateos='sudo -- sh -c "sudo apt update && sudo apt -y upgrade && sudo apt -y autoremove"'

# Load changes:
source ~/.zshrc

# List all aliases:
alias

Set local timezone

sudo unlink /etc/localtime
sudo ln -s /usr/share/zoneinfo/Europe/Rome /etc/localtime
sudo timedatectl set-timezone "Europe/Rome"

Set NTP

sudo apt install -y chrony
# You can configure which time servers you want to use by editing 
# nano /etc/chrony/chrony.conf

sudo systemctl enable --now chrony

sudo systemctl status chrony --no-pager
sudo timedatectl status
# System clock synchronized: yes
# NTP service: active

Set Keyboard layout

sudo dpkg-reconfigure keyboard-configuration

Disable Password prompt for sudo group

sudo sed -i.bak 's/%sudo\s\+ALL=(ALL:ALL) ALL/%sudo ALL=(ALL:ALL) NOPASSWD: ALL/' /etc/sudoers

Install packages (deb, etc)

sudo dpkg -i packname

First settings after O.S. install

passwd root
passwd kali
sudo apt install terminator -y
sudo update-alternatives --config x-terminal-emulator
# gsettings set org.gnome.desktop.default-applications.terminal exec 'terminator'

Set grub boot menu timeout

sudo nano /etc/default/grub

# Set the seconds in the GRUB_TIMEOUT value, save and exit the file
GRUB_TIMEOUT=1

sudo update-grub
# Reboot to test the timeout

# To instantly boot without the grub menu waiting, edit the file adding these lines:
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=0

Boot Partition Clean Up (Ubuntu/Debian)

# Check Current Kernel Version
sudo uname -r
# Example output: 5.4.0-64-generic
# As you see on image in my case – 5.4.0-64-generic is current kernel. Other older kernel versions can be deleted.

# List Old installed Kernel images:
sudo dpkg --list 'linux-image*'|awk '{ if ($1=="ii") print $2}'|grep -v `uname -r`

# Your output will something like:
linux-image-5.4.0-39-generic
linux-image-5.4.0-42-generic
linux-image-5.4.0-54-generic
linux-image-5.4.0-64-generic

# To cleanup boot partition in Ubuntu uninstall old kernels with apt command one by one:
sudo apt-get purge linux-image-5.4.0-39-generic
sudo apt-get purge linux-image-5.4.0-42-generic
sudo apt-get purge linux-image-5.4.0-54-generic

# Remove no longer used dependencies:
sudo apt-get autoremove

# Update GRUB:
sudo update-grub

Change Console setup

# For italian keyboard:
sudo dpkg-reconfigure console-setup

Disable Ubuntu automatic updates

sudo nano /etc/apt/apt.conf.d/20auto-upgrades
# make sure all the directives are set to “0”

sudo systemctl disable apt-daily-upgrade.timer
sudo systemctl mask apt-daily-upgrade.service
sudo systemctl disable apt-daily.timer
sudo systemctl mask apt-daily.service

# For complete package uninstall
sudo apt purge --auto-remove unattended-upgrades

Speedtest-cli

wget -O /dev/null -q --show-progress https://ash-speed.hetzner.com/10GB.bin

• Or install speedtest-cli

sudo apt install speedtest-cli

speedtest-cli --secure

Speedtest by Ookla

sudo apt install curl
curl -s https://packagecloud.io/install/repositories/ookla/speedtest-cli/script.deb.sh | sudo bash
sudo apt install speedtest

speedtest

Change password at boot - Single User Mode

# Start the Pc
# Press E in the grub menu
# Find the "linux /...vmlinuz" kernel line
# Add "init=/bin/bash" at the end of the line
# Press CTRL+X to boot.
# In root prompt, type 
mount -o remount,rw /
# Set a new password for a user with
passwd user
# or for the root user with
passwd
# Reboot
reboot -f

Check Hardware Temperatures

sudo apt install lm-sensors hddtemp
sudo sensors-detect
/etc/init.d/kmod start
sensors

# Raspberry Pi Temp
vcgencmd measure_temp

CPU Stress-Terminal UI - s-tui

sudo apt install s-tui stress

s-tui

# Output to default CSV file - s-tui_log_<TIME>.csv
s-tui --csv

Renew DHCP

sudo systemctl restart networking.service

# if doesn't work, release and renew IP with DHCP
sudo dhclient -r
sudo dhclient

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Software

Basic Tools

sudo apt install -y wget net-tools htop tree terminator flameshot

Install Zsh & Oh-My-Zsh

Install Eza

sudo sh -c '
    apt update &&
    apt install -y gpg &&
    mkdir -p /usr/share/keyrings &&
    wget -qO- https://raw.githubusercontent.com/eza-community/eza/main/deb.asc | gpg --dearmor -o /usr/share/keyrings/gierens.gpg &&
    echo "deb [arch=amd64 signed-by=/usr/share/keyrings/gierens.gpg] http://deb.gierens.de stable main" | tee /etc/apt/sources.list.d/gierens.list &&
    chmod 644 /usr/share/keyrings/gierens.gpg /etc/apt/sources.list.d/gierens.list &&
    apt update &&
    apt install -y eza
'

Install Sublime

sudo sh -c '
    wget -qO- https://download.sublimetext.com/sublimehq-pub.gpg | gpg --dearmor -o /usr/share/keyrings/sublimehq-archive.gpg &&
    echo "deb [arch="$(dpkg --print-architecture)" signed-by=/usr/share/keyrings/sublimehq-archive.gpg] https://download.sublimetext.com/ apt/stable/" | tee /etc/apt/sources.list.d/sublime-text.list &&
    apt update &&
    apt install -y sublime-text
'

Install VSCode

sudo apt update && sudo apt install -y software-properties-common apt-transport-https wget

sudo sh -c '
    wget -qO- https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor | sudo tee /usr/share/keyrings/packages.microsoft.gpg > /dev/null
    echo "deb [arch=amd64,arm64,armhf signed-by=//usr/share/keyrings/packages.microsoft.gpg] https://packages.microsoft.com/repos/code stable main" > /etc/apt/sources.list.d/vscode.list
    sudo apt update && sudo apt install -y code
'

EXTENSIONS=(
	mhutchie.git-graph \
	esbenp.prettier-vscode \
	redhat.vscode-yaml \
	oderwat.indent-rainbow \
	ms-python.python \
)

for EXT in "${EXTENSIONS[@]}"; do
	code --install-extension "$EXT"
done

Install VS Codium

wget https://gitlab.com/paulcarroty/vscodium-deb-rpm-repo/raw/master/pub.gpg && sudo mv pub.gpg /usr/share/keyrings/vscodium-archive-keyring.asc

sudo sh -c 'echo "deb [ signed-by=/usr/share/keyrings/vscodium-archive-keyring.asc ] https://paulcarroty.gitlab.io/vscodium-deb-rpm-repo/debs vscodium main" > /etc/apt/sources.list.d/vscodium.list'

sudo apt update && sudo apt install -y codium

Install Obsidian

# Download Obsidian latest release from https://github.com/obsidianmd/obsidian-releases/releases
mv Obsidian-0.12.4.AppImage usr/local/bin/obsidiann
chmod +x usr/local/bin/obsidian

Install Brave Browser

sudo sh -c '
    apt install -y curl
    curl -fsSLo /usr/share/keyrings/brave-browser-archive-keyring.gpg https://brave-browser-apt-release.s3.brave.com/brave-browser-archive-keyring.gpg
    echo "deb [arch="$(dpkg --print-architecture)" signed-by=/usr/share/keyrings/brave-browser-archive-keyring.gpg] https://brave-browser-apt-release.s3.brave.com/ stable main" | tee /etc/apt/sources.list.d/brave-browser-release.list
    wget http://archive.ubuntu.com/ubuntu/pool/main/libu/libu2f-host/libu2f-udev_1.1.10-3.2_all.deb
    dpkg -i libu2f-udev_1.1.10-3.2_all.deb
    apt update && apt install -y brave-browser
    rm -rf libu2f-udev_1.1.10-3.2_all.deb
'

Install GitHub Desktop

wget -qO- "https://mirror.mwt.me/shiftkey-desktop/install.sh" | sudo -s

# or
wget -qO - https://apt.packages.shiftkey.dev/gpg.key | gpg --dearmor | sudo tee /usr/share/keyrings/shiftkey-packages.gpg > /dev/null

sudo sh -c 'echo "deb [arch=amd64 signed-by=/usr/share/keyrings/shiftkey-packages.gpg] https://apt.packages.shiftkey.dev/ubuntu/ any main" > /etc/apt/sources.list.d/shiftkey-packages.list'

sudo apt update && sudo apt install github-desktop

Install Telegram

# Via apt
sudo apt install telegram-desktop

# Via official Linux binary

wget https://telegram.org/dl/desktop/linux
tar -xvf linux
sudo mv Telegram/ /opt
/opt/Telegram/./Telegram
/opt/Telegram/./Updater

Install Anydesk

# Run the following commands as root user:
# add repository key to Trusted software providers list
wget -qO - https://keys.anydesk.com/repos/DEB-GPG-KEY | apt-key add -

# add the repository:
sudo echo "deb http://deb.anydesk.com/ all main" > /etc/apt/sources.list.d/anydesk-stable.list

# update apt cache:
sudo apt update

# install anydesk:
sudo apt install -y anydesk

Install ForticlientVPN

sudo apt install firefox jq lz4json openfortivpn
cd
mkdir tools
cd ~/tools
git clone https://github.com/nonamed01/fuckForticlient.git
cd ~/tools/fuckForticlient

./fuckForticlient.sh -S <SERVER>:<PORT> -c
# Login via browser and retry the command above after logged in

Install DnsLeakTest

cd /tmp
wget https://raw.githubusercontent.com/macvk/dnsleaktest/master/dnsleaktest.py
chmod +x dnsleaktest.py
./dnsleaktest.py

Install Tor

sudo apt install -y tor
service tor start
service tor status

# Start browser with proxychain:
proxychains firefox www.duckduckgo.com
	(do not close terminal)

# search for: check dns leaks

Install Anonsurf

cd /tmp
git clone https://github.com/Und3rf10w/kali-anonsurf
cd kali-anonsurf/
./installer.sh
clear
cd

anonsurf --help
anonsurf start

anonsurf myip

Install Metasploit Framework

curl https://raw.githubusercontent.com/rapid7/metasploit-omnibus/master/config/templates/metasploit-framework-wrappers/msfupdate.erb > msfinstall && chmod 755 msfinstall && ./msfinstall

• Or use APT package manager on Debian-based distros

sudo apt update && sudo apt install -y metasploit-framework

• Enable postgresql at boot, start the service and initialize MSF database

sudo systemctl enable postgresql
sudo systemctl restart postgresql
sudo msfdb init

• Run msfconsole to start the Metasploit Framework Console

msfconsole

Install Nessus

Install Docker

sudo apt update && sudo apt install -y curl apt-transport-https software-properties-common ca-certificates gnupg

packages=("docker.io" "docker-doc" "docker-compose" "podman-docker" "containerd" "runc")
for pkg in "${packages[@]}"; do
    sudo apt remove "$pkg" -y
done &&

sudo sh -c '
    curl -fsSL https://download.docker.com/linux/debian/gpg | gpg --dearmor -o /usr/share/keyrings/docker.gpg &&
    chmod a+r /usr/share/keyrings/docker.gpg &&
    echo "deb [arch="$(dpkg --print-architecture)" signed-by=/usr/share/keyrings/docker.gpg] https://download.docker.com/linux/debian bullseye stable" |  tee /etc/apt/sources.list.d/docker.list &&
    apt update && 
    apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin &&
    sudo gpasswd -a "${USER}" docker
'

Install Gophish

cd /opt/

# Get the latest version link from https://github.com/gophish/gophish/releases/
sudo wget https://github.com/gophish/gophish/releases/download/v0.12.1/gophish-v0.12.1-linux-64bit.zip

sudo unzip -d gophish gophish-v0.12.1-linux-64bit.zip

sudo chmod +x gophish/gophish

cd /opt/gophish && sudo ./gophish

• Setup a Gophish Demo with a fake campaign

docker run -ti -p 3333:3333 --rm gophish/demo

Install Katana

sudo apt install -y golang

go install github.com/projectdiscovery/katana/cmd/katana@latest

sudo cp ~/go/bin/katana /bin/

Install Asbru CM (Linux Desktop)

• Link Asbru

• Ásbrú Connection Manager is a user interface that helps organizing remote terminal sessions and automating repetitive tasks.

curl -1sLf 'https://dl.cloudsmith.io/public/asbru-cm/release/cfg/setup/bash.deb.sh' | sudo -E bash
sudo apt install -y asbru-cm

Install BurpSuite

• Link BurpSuite Community Download

  • Use this for updating too

# Download Burp Suite community edition for Linux 64 bits 
BURP_VER=$(curl -si https://portswigger.net/burp/releases/community/latest | grep -E "^location:" | grep -Eo "[0-9]+.[0-9]+.[0-9]+" | sed 's/-/./g')

wget -qO "/tmp/burpsuite_community_v"$BURP_VER"_install.sh" "https://portswigger.net/burp/releases/startdownload?product=community&version="$BURP_VER"&type=Linux"

chmod +x "/tmp/burpsuite_community_v"$BURP_VER"_install.sh"
sudo /tmp/burpsuite_community_v"$BURP_VER"_install.sh -q

# Default install dir is /opt/BurpSuiteCommunity
# This will overwrite the command of the already installed Burpsuite (with apt)

sudo cp /opt/BurpSuiteCommunity/burpsuite_community.jar /usr/share/burpsuite/burpsuite.jar
sudo mv /usr/bin/burpsuite /usr/bin/burpsuite.bak
echo -ne '#!/bin/sh\n"/opt/BurpSuiteCommunity/BurpSuiteCommunity" %U\n' | sudo tee /usr/bin/burpsuite && sudo chmod +x /usr/bin/burpsuite

# Start burspsuite from shell

Install MobSF

sudo mkdir -p ~/docker/mobsf

chown 9901:9901 ~/docker/mobsf

docker run -it --rm --name mobsf -p 8010:8010 -v ~/docker/mobsf:/home/mobsf/.MobSF opensecurity/mobile-security-framework-mobsf:latest

Install Rustscan

docker run -it --rm --name rustscan rustscan/rustscan:2.1.1

# Create a zsh/bash alias like this
alias rustscan='docker run -it --rm --name rustscan rustscan/rustscan:2.1.1'

Install CVEMAP

sudo apt install -y golang-go

go install github.com/projectdiscovery/cvemap/cmd/cvemap@latest

# Based on your SHELL, add Go bin to system PATH
echo "export PATH=$PATH:$HOME/go/bin" >> $HOME/.bashrc
echo "export PATH=$PATH:$HOME/go/bin" >> $HOME/.zshrc
echo "export PATH=$PATH:$HOME/go/bin" >> $ZSH_CUSTOM/my_paths.zsh
source $HOME/.bashrc
source $HOME/.zshrc

---

Usage and Configuration

SSH Login

sudo systemctl enable ssh --now

Configure Git for Github

git config --global user.email "[e-mail]"
git config --global user.name"YOUR_USERNAME"

ssh-keygen -t ed25519 -C "[e-mail]"
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519
xclip -selection clipboard < ~/.ssh/id_ed25519.pub

# Add a new key on github.com and paste the one copied with xclip.
# Test it:
ssh -T [e-mail]

git clone [e-mail]:syselement/REPOSITORY.git

Proxychains

#Edit proxychains:
nano /etc/proxychains.conf
# uncoment dynamic_chain
# coment strict_chain
# uncoment Proxy DNS requests-no leak for DNS data
# add on proxylist: socks5 127.0.0.1 9050

OpenVpn

# TryHackme OpenVpn Cypher(Temporary) error fix 
sed -i 's/cipher AES-256-CBC/data-ciphers AES-256-CBC/' yournickname.ovpn

# or
sudo nano yournickname.ovpn
# Substitute line 14 "cipher AES-256-CBC" with:
data-ciphers AES-256-CBC

# Launch openvpn connection in background as a daemon
sudo openvpn --config yournickname.ovpn --daemon

# Stop it
sudo pkill -f openvpn

NMAP

nmap 192.168.254.129
nmap 192.168.254.1/24
nmap 192.168.254.1-100
nmap -p80,21,23 192.168.254.129

RDP with Xfce (Kali Linux)

🔗 Setting up RDP with Xfce - Kali Linux

wget https://gitlab.com/kalilinux/recipes/kali-scripts/-/raw/main/xfce4.sh
chmod +x xfce4.sh
sudo ./xfce4.sh

sudo adduser xrdp ssl-cert
sudo systemctl enable xrdp --now

• The xfce4.sh does the following

#!/bin/bash
echo "[i] Updating and upgrading Kali (this will take a while)"
apt-get update
apt-get --yes --force-yes dist-upgrade

echo "[i] Installing Xfce4 & xrdp (this will take a while as well)"
apt-get --yes --force-yes install kali-desktop-xfce xorg xrdp

echo "[i] Configuring xrdp to listen to port 3390 (but not starting the service)"
sed -i 's/port=3389/port=3390/g' /etc/xrdp/xrdp.ini

• Fix for Authentication Required to Create Managed Color Device, run

cat <<EOF | sudo tee /etc/polkit-1/localauthority/50-local.d/45-allow-colord.pkla
[Allow Colord all Users]
Identity=unix-user:*
Action=org.freedesktop.color-manager.create-device;org.freedesktop.color-manager.create-profile;org.freedesktop.color-manager.delete-device;org.freedesktop.color-manager.delete-profile;org.freedesktop.color-manager.modify-device;org.freedesktop.color-manager.modify-profile
ResultAny=no
ResultInactive=no
ResultActive=yes
EOF

sudo systemctl restart xrdp

• Port to connect to is 3390

### TESTS - DO NOT CONSIDER ###

# sudo nano /etc/xrdp/startwm.sh

# # Add lines before test and execute
# unset DBUS_SESSION_BUS_ADDRESS
# unset XDG_RUNTIME_DIR
# . $HOME/.profile

Arm on x86 QEMU-USER

🔗 Running arm binaries on x86 with qemu-user

sudo apt update -y && sudo apt upgrade -y
sudo apt install qemu-user qemu-user-static gcc-aarch64-linux-gnu binutils-aarch64-linux-gnu binutils-aarch64-linux-gnu-dbg build-essential libc6-dev-arm64-cross

qemu-aarch64-static -L /usr/aarch64-linux-gnu/ sandbox

---

Virtual Machines

Install VirtualBox on Kali

🔗 Install VirtualBox on Kali (Host)

sudo apt update

curl -fsSL https://www.virtualbox.org/download/oracle_vbox_2016.asc|sudo gpg --dearmor -o /etc/apt/trusted.gpg.d/oracle_vbox_2016.gpg

curl -fsSL https://www.virtualbox.org/download/oracle_vbox.asc|sudo gpg --dearmor -o /etc/apt/trusted.gpg.d/oracle_vbox.gpg

echo "deb [arch=amd64] https://download.virtualbox.org/virtualbox/debian bullseye contrib" | sudo tee /etc/apt/sources.list.d/virtualbox.list

sudo apt update

sudo apt install -y dkms

sudo apt install -y virtualbox virtualbox-ext-packv

VirtManager backup qcow2 VM

# Backup VMs

sudo -s
# Now that the terminal is using root, run the virsh tool to create a backup of the VM definitions file.

echo '' > nameofvm.xml
virsh dumpxml nameofvm >  /var/lib/libvirt/images/nameofvm.xml
# Use ls to find the name of the Qcow2 virtual hard drive in /var/lib/libvirt/images/. Copy the file name, and use mv to move it into a new sub-directory.

mkdir -p vm-backup
cd vm-backup
mv example.qcow2 vm-backup

mv nameofvm.xml vm-backup


# Using tar, create an archive of the VM disk and XML file.
tar jcvfp my-vm-backup.tar.bz2 vm-backup

mv my-vm-backup.tar.bz2 /home/username/
# Backing up VM disk images takes a long time. Depending on the file size, it could take an hour or more. Best to just let the PC do its thing. When the backup is complete, feel free to move my-vm-backup.tar.bz2 to another server, cloud backup and etc.


# Restoring backups
To restore a backup, you’ll first need to extract it.

tar xvfp my-vm-backup.tar.bz2
cd vm-backup

# Use virsh to restore the XML file.
sudo -s
virsh define --file /home/username/location/of/exctracted/archive/vm-backup/nameofvm.xml

# Lastly, move the disk image to the images directory.
mv example.qcow2 /var/lib/libvirt/images/

METASPLOITABLE VM

📌 Check Metasploitable3 VM here

• Metasploitable2 - Download link

• Guides:

  • Metasploitable 2

  • Metasploitable 2 Exploitability Guide

# Login: msfadmin:msfadmin

---

Troubleshooting

---

Logs

ls -lah /var/log/

auth.log
boot.log
cron.log
httpd
dpkg.log
kern.log
syslog
user.log
...

/var/log/apache2/access.log
/var/log/apache2/error.log