Below is a collection of useful (and free) tools, what I use them for and where to get them.

Please note: I am not sponsored by or affiliated with the creators of any of the software listed below. While these tools are useful to me, your mileage may vary. Use them at your own risk and discretion!

WiresharkGerald CombsProtocol AnalyzerLink
OpenVASGreenbone NetworksVulnerability Assessment ScannerLink
Kali LinuxOffensive SecurityLinux distribution for digital forensics and penetration testingLink
VirtualBoxOracleHost-based HypervisorLink
SpaceSnifferUderzo SoftwareTreemap File VisualizationLink
Notepad++Don HoText EditorLink
Nmap/ZenmapGordon "Fyodor" LyonNetwork Discovery and Security AuditingLink
PuTTYSimon TathamSSH/Telnet ClientLink
Angry IP ScannerAnton KeksFast/Simple Network ScannerLink
Hiren's Boot CD PE"Fans of Hiren" [sic]A collection of system recovery tools on a bootable image.Link
VeraCryptIDRIXDisk EncryptionLink
Canary TokensThinkst Applied ResearchBreach Detection/HoneypotLink
SMTP Diag ToolAdminKit.netSMTP diagnostics toolLink
Mouse Without BordersMicrosoft GarageFree Software KVMLink
SysInternals SuiteMicrosoftWindows systems administration toolsLink

I’ve also included some websites I’ve come across and found useful and/or informative.

Please note: I am not sponsored by or affiliated with any of the sites below. I make no guarantees or warranties as to the accuracy or completeness of the information therein. Browse at your own discretion.

Site/Tool NameDescriptionLink
ParseMailEmail header information parser. Provides a clean and clear interface to inspect MIME parts for determining where a message came from.
MX ToolboxFree [primarily email related] tools. Useful for checking your mail servers against blacklists.
OUI Lookup tablesA set of Organization Unique Identifiers you can use to look up registered manufacturers using the first 24 bits of their MAC address
UdemyInexpensive online learning platform. Useful for certification prep.
Black ViperFor over 20 years, Charles "Black Viper" Sparks has been putting out great content, most notably his Windows Services guides. He's an all-around cool cat and I suggest you check him out!