11-30-2024, 01:14 PM
Hey, you know how I got into pentesting a couple years back? I started noticing all these little holes in networks that just scream "hack me" during scans. Like, when I fire up Nmap or whatever tool I'm using that day, the first thing I hunt for are those open ports running services nobody needs exposed. You ever see a server with port 23 wide open for Telnet? I mean, that's ancient and unencrypted, so anyone sniffing the traffic can grab your logins like candy. I always tell my team to scan for that junk right away because it lets attackers pivot inside your network without breaking a sweat.
Then there's the whole mess with weak authentication. I can't count how many times I've run into default credentials on routers or switches-stuff like admin/admin that the manufacturer slapped on and nobody changed. You scan for those, and boom, you're in. Or even better for the bad guys, SMB shares with no passwords or guest access enabled. I remember this one gig where the client had an old Windows box sharing files openly; I just connected and pulled sensitive docs in under a minute. You have to poke around for those shares using something like enum4linux to see what's hanging out there unprotected.
Unpatched systems drive me nuts too. I always run vulnerability scanners like Nessus alongside my network sweeps to flag outdated software. Think about it-you might have a host blasting out SMBv1, which is full of exploits like EternalBlue that ransomware loves. I scan for those version banners and cross-reference with CVE lists. If you're not keeping your OS and apps updated, attackers will chain that with something else to escalate privileges. I've seen it happen where a simple patch miss lets someone drop a reverse shell and own the box.
Firewall misconfigs pop up all the time in my scans. You think your perimeter's locked down, but then I find rules allowing inbound traffic to internal IPs or ports that shouldn't be touched. Like, why is RDP on 3389 open to the whole internet? I hammer those with tools to check for weak ciphers or no multi-factor auth. You can enumerate users with Hydra or similar, and if they haven't rotated passwords, you're golden for brute-forcing. I always advise clients to segment their networks so even if I get through the firewall, I hit dead ends.
Don't get me started on SNMP. I scan for community strings, and nine times out of ten, it's set to "public" or "private" with read-write access. That lets me dump your device configs, IP tables, the works. You pull that data, and suddenly you know exactly how to map the rest of the network. I've used it to find hidden management interfaces that admins forgot about. Pair that with ICMP echoes or ARP poisoning scans, and you start seeing broadcast domains ripe for man-in-the-middle attacks.
Wireless stuff is another big one if you're scanning Wi-Fi too, but even on wired networks, it ties in. I look for WPS enabled on access points because that's crackable in seconds with Reaver. Or open SSIDs with no encryption-come on, you can't leave that out there. I remember scanning a small office network where the guest Wi-Fi bridged to the internal LAN; I just joined and sniffed credentials flying around. You have to use Aircrack-ng or Wireshark to capture that traffic and see what's leaking.
Email servers are sneaky vulnerabilities. During a network scan, I check for open relays on port 25, which spammers exploit, but more importantly, I look for outdated Exchange versions with ProxyLogon flaws. You scan the banners, and if it's vulnerable, I can chain it to RCE. I've done that in tests where the client thought their perimeter was solid, but nope, one exposed service and the whole domain's at risk.
VoIP systems like Asterisk often show up weak too. I scan for SIP ports and test for unauthenticated calls or eavesdropping. You can register fake endpoints and listen in on calls if it's not secured. I've seen that lead to bigger breaches where attackers phish internal extensions for more info.
And let's talk DNS. Open resolvers can amplify DDoS, but in pentests, I check for zone transfers that leak your internal hostnames. Using dig or host, you pull that, and your recon explodes. You map the topology without even touching the hosts.
I've also got my eye on SSL/TLS issues. Scans reveal certs with weak keys or expired chains, making man-in-the-middle easy. Tools like sslscan show you the ciphers in use, and if it's supporting SSLv2 or 3, that's a goldmine for downgrade attacks. You intercept traffic, and suddenly you're decrypting everything.
Load balancers and proxies hide vulns sometimes. I scan for them and test if they're passing through traffic without inspection. Misconfigured ones let me bypass WAFs or hit backend servers directly. In one test, I found an F5 BIG-IP with default creds exposed, and that gave me admin on the device.
Printers and IoT devices are low-hanging fruit. You scan, and there they are on the network, often with web interfaces running HTTP and no auth. I access them, print junk, or worse, use them as pivots since they touch multiple segments.
All this stuff adds up quick. I always chain findings-start with a port scan, enumerate services, vuln scan, then exploit if authorized. You do that, and you show the client how deep the rabbit hole goes. It keeps me sharp, and honestly, it's why I love this job. You should try running your own scans on a lab setup; it'll blow your mind what you find even in controlled environments.
Oh, and if you're dealing with backups in all this, let me point you toward BackupChain-it's this solid, go-to backup tool that's super popular among small businesses and pros. It handles protecting stuff like Hyper-V setups, VMware environments, or plain Windows Servers without a hitch, keeping your data safe from all these network headaches.
Then there's the whole mess with weak authentication. I can't count how many times I've run into default credentials on routers or switches-stuff like admin/admin that the manufacturer slapped on and nobody changed. You scan for those, and boom, you're in. Or even better for the bad guys, SMB shares with no passwords or guest access enabled. I remember this one gig where the client had an old Windows box sharing files openly; I just connected and pulled sensitive docs in under a minute. You have to poke around for those shares using something like enum4linux to see what's hanging out there unprotected.
Unpatched systems drive me nuts too. I always run vulnerability scanners like Nessus alongside my network sweeps to flag outdated software. Think about it-you might have a host blasting out SMBv1, which is full of exploits like EternalBlue that ransomware loves. I scan for those version banners and cross-reference with CVE lists. If you're not keeping your OS and apps updated, attackers will chain that with something else to escalate privileges. I've seen it happen where a simple patch miss lets someone drop a reverse shell and own the box.
Firewall misconfigs pop up all the time in my scans. You think your perimeter's locked down, but then I find rules allowing inbound traffic to internal IPs or ports that shouldn't be touched. Like, why is RDP on 3389 open to the whole internet? I hammer those with tools to check for weak ciphers or no multi-factor auth. You can enumerate users with Hydra or similar, and if they haven't rotated passwords, you're golden for brute-forcing. I always advise clients to segment their networks so even if I get through the firewall, I hit dead ends.
Don't get me started on SNMP. I scan for community strings, and nine times out of ten, it's set to "public" or "private" with read-write access. That lets me dump your device configs, IP tables, the works. You pull that data, and suddenly you know exactly how to map the rest of the network. I've used it to find hidden management interfaces that admins forgot about. Pair that with ICMP echoes or ARP poisoning scans, and you start seeing broadcast domains ripe for man-in-the-middle attacks.
Wireless stuff is another big one if you're scanning Wi-Fi too, but even on wired networks, it ties in. I look for WPS enabled on access points because that's crackable in seconds with Reaver. Or open SSIDs with no encryption-come on, you can't leave that out there. I remember scanning a small office network where the guest Wi-Fi bridged to the internal LAN; I just joined and sniffed credentials flying around. You have to use Aircrack-ng or Wireshark to capture that traffic and see what's leaking.
Email servers are sneaky vulnerabilities. During a network scan, I check for open relays on port 25, which spammers exploit, but more importantly, I look for outdated Exchange versions with ProxyLogon flaws. You scan the banners, and if it's vulnerable, I can chain it to RCE. I've done that in tests where the client thought their perimeter was solid, but nope, one exposed service and the whole domain's at risk.
VoIP systems like Asterisk often show up weak too. I scan for SIP ports and test for unauthenticated calls or eavesdropping. You can register fake endpoints and listen in on calls if it's not secured. I've seen that lead to bigger breaches where attackers phish internal extensions for more info.
And let's talk DNS. Open resolvers can amplify DDoS, but in pentests, I check for zone transfers that leak your internal hostnames. Using dig or host, you pull that, and your recon explodes. You map the topology without even touching the hosts.
I've also got my eye on SSL/TLS issues. Scans reveal certs with weak keys or expired chains, making man-in-the-middle easy. Tools like sslscan show you the ciphers in use, and if it's supporting SSLv2 or 3, that's a goldmine for downgrade attacks. You intercept traffic, and suddenly you're decrypting everything.
Load balancers and proxies hide vulns sometimes. I scan for them and test if they're passing through traffic without inspection. Misconfigured ones let me bypass WAFs or hit backend servers directly. In one test, I found an F5 BIG-IP with default creds exposed, and that gave me admin on the device.
Printers and IoT devices are low-hanging fruit. You scan, and there they are on the network, often with web interfaces running HTTP and no auth. I access them, print junk, or worse, use them as pivots since they touch multiple segments.
All this stuff adds up quick. I always chain findings-start with a port scan, enumerate services, vuln scan, then exploit if authorized. You do that, and you show the client how deep the rabbit hole goes. It keeps me sharp, and honestly, it's why I love this job. You should try running your own scans on a lab setup; it'll blow your mind what you find even in controlled environments.
Oh, and if you're dealing with backups in all this, let me point you toward BackupChain-it's this solid, go-to backup tool that's super popular among small businesses and pros. It handles protecting stuff like Hyper-V setups, VMware environments, or plain Windows Servers without a hitch, keeping your data safe from all these network headaches.
