SMB Shares: The Quiet Source of Many Breaches
SMB shares are unglamorous. They do not get conference talks. They do, however, host most of the credentials, configuration files, customer data, and backup keys that attackers find on internal engagements.
Network · By Thimmagurudu Bathini · Published · 5 min read · Last reviewed
What we look for
We enumerate every share on every host (CrackMapExec, smbmap), then walk the readable ones recursively. The interesting files have predictable names: web.config, .env, credentials.txt, unattend.xml, sysprep.inf, id_rsa, connection_strings.config, anything ending in .kdbx (KeePass database), and Group Policy Preferences files with cpassword fields (still crackable to plaintext).
Typical findings
- Domain admin credentials in a deployment script on a share readable by Domain Users
- Backup files of the SAM and SYSTEM hives, allowing offline credential extraction
- SQL connection strings with sa-equivalent privileges in
web.config - Personal data (PAN, Aadhaar, customer records) on an HR share with Everyone read
- Source code repositories mirrored to a file share with permissive ACLs
The fix is unglamorous too
Audit share permissions. Remove Everyone and Authenticated Users from anything sensitive. Enable SMB signing and disable SMBv1. Block SMB at the host firewall on workstations (no business need for inbound SMB to a laptop). Move secrets out of file shares and into a vault.
Our internal network playbook covers the full enumeration flow.
Written by Thimmagurudu Bathini, BERRY9 IT SERVICES PRIVATE LIMITED, Hyderabad. Questions about your own systems? Request a scoping call or call +91 86868 92922.
Plan your next security test
Tell us what needs testing and when you need it done, and we will propose a scope and timeline. We respond within 24 hours. If you would rather talk first, call or write to us.
- +91 86868 92922
- contact@berry9.com
- H.No: 8-3-945/A/12 & 13, Sri Venkata Sai Nest Apartments, Nagarjuna Nagar Colony, Yellareddyguda, Hyderabad 500073, Telangana