rsa_usa_2019_paula_januszkiewicz
- 1. #RSAC SESSION ID: Paula Januszkiewicz Understand Credential Security: Important Things You Need to Know About Storing Your Identity IDY-W03 CQURE: CEO, Penetration Tester / Security Expert CQURE Academy: Trainer MVP: Enterprise Security, MCT Microsoft Regional Director Contact: paula@cqure.us | http://cqure.us
- 2. #RSAC
- 3. #RSAC
- 5. #RSAC Bootkey: Class names for keys from HKLMSYSTEMCCSControlLsa SAM/NTDS.dit (MD4 Hashes) C:windowssystem32config C:windowssystem32NTDS MSDCC2 (Cached Logon Data) HKLMSECURITYCache LSA Secrets (Service Accounts) HKLMSECURITYPolicySecrets $MACHINE.ACC (SYSTEM’s Clear Text Password) DPAPI_SYSTEM (Master Keys) HKLMSECURITYPolicySecrets
- 6. #RSAC Are ‘cached credentials’ safe?
- 7. #RSAC Encrypted Cached Credentials DK = PBKDF2(PRF, Password, Salt, c, dkLen) Microsoft’s implementation: MSDCC2= PBKDF2(HMAC-SHA1, DCC1, username, 10240, 16) Encrypted Cached Credentials: Legend
- 8. #RSAC Cached Logons: It used to be like this… The encryption algorithm is RC4. The hash is used to verify authentication is calculated as follows: DCC1 = MD4(MD4(Unicode(password)) . LowerUnicode(username)) is DCC1 = MD4(hashNTLM . LowerUnicode(username)) Before the attacks facilitated by pass-the-hash, we can only rejoice the "salting" by the username. There are a number pre-computed tables for users as Administrator facilitating attacks on these hashes.
- 9. #RSAC Cached Logons: Now it is like this! The encryption algorithm is AES128. The hash is used to verify authentication is calculated as follows: MSDCC2 = PBKDF2(HMAC-SHA1, Iterations, DCC1, LowerUnicode(username)) with DCC 1 calculated in the same way as for 2003 / XP. There is actually not much of a difference with XP / 2003! No additional salting. PBKDF2 introduced a new variable: the number of iterations SHA1 with the same salt as before (username).
- 10. #RSAC Cached Logons: Iterations The number of iterations in PBKDF2, it is configurable through the registry: HKEY_LOCAL_MACHINESECURITYCache DWORD (32) NL$IterationCount If the number is less than 10240, it is a multiplier by 1024 (20 therefore gives 20480 iterations) If the number is greater than 10240, it is the number of iterations (rounded to 1024)
- 12. #RSAC Classic Data Protection API Based on the following components: Password, data blob, entropy Is not prone to password resets! Protects from outsiders when being in offline access Effectively protects users data Stores the password history You need to be able to get access to some of your passwords from the past Conclusion:OS greatlyhelpsustoprotectsecrets
- 13. #RSAC + getting access to user’s secrets in the domain Demo: Classic DPAPI
- 14. #RSAC + Keepass Demo: DPAPI Taken Further
- 15. #RSAC When centralization should be done with a bit more awareness Demo: RDG Passwords
- 17. #RSAC Application Pools Used to group one or more Web Applications Purpose: Assign resources, serve as a security sandbox Use Worker Processes (w3wp.exe) Their identity is defined in Application Pool settings Process requests to the applications Passwords for AppPool identity can be ’decrypted’ even offline They are stored in the encrypted form in applicationHost.config Conclusion: IIS relies it’s securityon Machine Keys(Local System)
- 18. #RSAC Getting password from IIS configuration Demo: Application Pools
- 19. #RSAC + extracting the data from the registry IISWasKey
- 20. #RSAC Services Store configuration in the registry Always need some identity to run the executable! Local Security Authority (LSA) Secrets Must be stored locally, especially when domain credentials are used Can be accessed when we impersonate to Local System Their accounts should be monitored If you cannot use gMSA, MSA, use subscription for svc_ accounts (naming convention) Conclusion: Think twice before using an Administrativeaccount, use gMSA
- 21. #RSAC Getting password from LSA Secrets Demo: Services
- 22. #RSAC Chasing the obvious: NTDS.DIT, SAM Theabovemeans:Toreadthecleartextpasswordyouneedtostruggle!
- 23. #RSAC Hash spree - offline Demo: SAM/NTDS.dit
- 24. #RSAC
- 25. #RSAC Two AMAZING discoveries! Smart card logon is possible without a smart card Private keys can be extracted from the PFX files without having a password
- 26. #RSAC Securing Yourself for a Rainy Day Kerberos Pre-Auth
- 27. #RSAC SID-Protected PFX Files… Unprotected DPAPI-NG
- 28. #RSAC Credentials Security Takeways Cryptography that relies on keys stored in the registry is as safe as your offline access. We all know that they should log on to the Domain Controllers only. Who are they? Can we trust them? …when extracted. In practice they are as safe as your approach.
- 29. Thank you!
- 30. #RSAC SESSION ID: Paula Januszkiewicz Understand Credential Security: Important Things You Need to Know About Storing Your Identity IDY-W03 CQURE: CEO, Penetration Tester / Security Expert CQURE Academy: Trainer MVP: Enterprise Security, MCT Microsoft Regional Director Contact: paula@cqure.us | http://cqure.us