RPC

RPCclient

realblackcat@htb[/htb]$ rpcclient -U "" - N 10.129.14.128

Enter WORKGROUP\'s password:
rpcclient $>

rpcclien는 smb 서버에서 특정 함수를 실행하여 정보를 얻을 수 있는 다양한 요청을 제공

쿼리

설명

srvinfo

서버 정보

enumdomains

네트워크에 배포된 모든 도메인 열거

querydominfo

배포된 도메인의 도메인, 서버 및 사용자 정보를 제공합니다.

netshareenumall

사용 가능한 모든 공유를 열거합니다.

netsharegetinfo <share>

특정 공유에 대한 정보를 제공합니다.

enumdomusers

모든 도메인 사용자를 열거합니다.

queryuser <RID>

특정 사용자에 대한 정보를 제공합니다.

RPCclient – Enumeration

rpcclient $> srvinfo #서버 정보 

        DEVSMB         Wk Sv PrQ Unx NT SNT DEVSM
        platform_id     :       500
        os version      :       6.1
        server type     :       0x809a03
		
		
rpcclient $> enumdomains #네트워크에 배포된 모든 도메인 열거 

name:[DEVSMB] idx:[0x0]
name:[Builtin] idx:[0x1]


rpcclient $> querydominfo #배포된 도메인의 도메인, 서버 및 사용자 정보를 제공합니다.

Domain:         DEVOPS
Server:         DEVSMB
Comment:        DEVSM
Total Users:    2
Total Groups:   0
Total Aliases:  0
Sequence No:    1632361158
Force Logoff:   -1
Domain Server State:    0x1
Server Role:    ROLE_DOMAIN_PDC
Unknown 3:      0x1


rpcclient $> netshareenumall #사용 가능한 모든 공유를 열거합니다.

netname: print$
        remark: Printer Drivers
        path:   C:\var\lib\samba\printers
        password:
netname: home
        remark: INFREIGHT Samba
        path:   C:\home\
        password:
netname: dev
        remark: DEVenv
        path:   C:\home\sambauser\dev\
        password:
netname: notes
        remark: CheckIT
        path:   C:\mnt\notes\
        password:
netname: IPC$
        remark: IPC Service (DEVSM)
        path:   C:\tmp
        password:
		
		
rpcclient $> netsharegetinfo notes #특정 공유에 대한 정보를 제공합니다.

netname: notes
        remark: CheckIT
        path:   C:\mnt\notes\
        password:
        type:   0x0
        perms:  0
        max_uses:       -1
        num_uses:       1
revision: 1
type: 0x8004: SEC_DESC_DACL_PRESENT SEC_DESC_SELF_RELATIVE 
DACL
        ACL     Num ACEs:       1       revision:       2
        ---
        ACE
                type: ACCESS ALLOWED (0) flags: 0x00 
                Specific bits: 0x1ff
                Permissions: 0x101f01ff: Generic all access SYNCHRONIZE_ACCESS WRITE_OWNER_ACCESS WRITE_DAC_ACCESS READ_CONTROL_ACCESS DELETE_ACCESS 
                SID: S-1-1-0

이 예는 익명 사용자에게 어떤 정보가 유출될 수 있는지 보여줌
가장 중요한 것은 이러한 서비스에 익명으로 액세스하면 다른 사용자가 발견될 수 있으며, 가장 공격적인 경우 무차별 대입 공격을 받을 수 있음.
- rpcclient를 사용하여 사용자를 열거하는 방법을 살펴보자

Rpcclient – 사용자 열거형

rpcclient $> enumdomusers #모든 도메인 사용자를 열거합니다.

user:[mrb3n] rid:[0x3e8]
user:[cry0l1t3] rid:[0x3e9]


rpcclient $> queryuser 0x3e9 #특정 사용자에 대한 정보를 제공합니다.

        User Name   :   cry0l1t3
        Full Name   :   cry0l1t3
        Home Drive  :   \\devsmb\cry0l1t3
        Dir Drive   :
        Profile Path:   \\devsmb\cry0l1t3\profile
        Logon Script:
        Description :
        Workstations:
        Comment     :
        Remote Dial :
        Logon Time               :      Do, 01 Jan 1970 01:00:00 CET
        Logoff Time              :      Mi, 06 Feb 2036 16:06:39 CET
        Kickoff Time             :      Mi, 06 Feb 2036 16:06:39 CET
        Password last set Time   :      Mi, 22 Sep 2021 17:50:56 CEST
        Password can change Time :      Mi, 22 Sep 2021 17:50:56 CEST
        Password must change Time:      Do, 14 Sep 30828 04:48:05 CEST
        unknown_2[0..31]...
        user_rid :      0x3e9
        group_rid:      0x201
        acb_info :      0x00000014
        fields_present: 0x00ffffff
        logon_divs:     168
        bad_password_count:     0x00000000
        logon_count:    0x00000000
        padding1[0..7]...
        logon_hrs[0..21]...


rpcclient $> queryuser 0x3e8

        User Name   :   mrb3n
        Full Name   :
        Home Drive  :   \\devsmb\mrb3n
        Dir Drive   :
        Profile Path:   \\devsmb\mrb3n\profile
        Logon Script:
        Description :
        Workstations:
        Comment     :
        Remote Dial :
        Logon Time               :      Do, 01 Jan 1970 01:00:00 CET
        Logoff Time              :      Mi, 06 Feb 2036 16:06:39 CET
        Kickoff Time             :      Mi, 06 Feb 2036 16:06:39 CET
        Password last set Time   :      Mi, 22 Sep 2021 17:47:59 CEST
        Password can change Time :      Mi, 22 Sep 2021 17:47:59 CEST
        Password must change Time:      Do, 14 Sep 30828 04:48:05 CEST
        unknown_2[0..31]...
        user_rid :      0x3e8
        group_rid:      0x201
        acb_info :      0x00000010
        fields_present: 0x00ffffff
        logon_divs:     168
        bad_password_count:     0x00000000
        logon_count:    0x00000000
        padding1[0..7]...
        logon_hrs[0..21]...

이제 이 결과를 사용하여 그룹의 RID를 식별한 다음 전체 그룹에서 정보를 검색하는데 사용할 수 있음

Rpcclient – 그룹 정보

rpcclient $> querygroup 0x201

        Group Name:     None
        Description:    Ordinary Users
        Group Attribute:7
        Num Members:2

이 모든 명령을 사용할 수 있는 것은 아님, 사용자에 따라 특정 제한이 있을 수 잇음 but user<RID>에 대한 쿼리는 대부분 RID를 기반으로 허용되므로 rcpclient를 사용하여 무차별 대입을 통해 정보를 얻을 수 있음.
- 이를 사용하기 위한 도구는 여러가지가 존재, 이런 도구를 계속 사용하려면 bash를 사용하여 for 루프를 만들어서 rcpclient를 사용하여 서비스에 명령을 전송하고 결과를 필터링할 수 있음

무차별 사용자 RID 강제 적용

realblackcat@htb[/htb]$ for i in $(seq 500 1100);do rpcclient -N -U "" 10.129.14.128 -c "queryuser 0x$(printf '%x\n' $i)" | grep "User Name\|user_rid\|group_rid" && echo "";done

        User Name   :   sambauser
        user_rid :      0x1f5
        group_rid:      0x201
		
        User Name   :   mrb3n
        user_rid :      0x3e8
        group_rid:      0x201
		
        User Name   :   cry0l1t3
        user_rid :      0x3e9
        group_rid:      0x201

이에 대한 대안으로 samrdump.py를 사용할 수 있음

Samrdump.py

realblackcat@htb[/htb]$ sfor i in $(seq 500 1100); do
    rpcclient -N -U "" [IP_ADDRESS] -c "queryuser 0x$(printf '%x\n' $i)" | grep "User Name\|user_rid\|group_rid" && echo "";
donefor i in $(seq 500 1100); do
    rpcclient -N -U "" [IP_ADDRESS] -c "queryuser 0x$(printf '%x\n' $i)" | grep "User Name\|user_rid\|group_rid" && echo "";
done10.129.14.128

Impacket v0.9.22 - Copyright 2020 SecureAuth Corporation

[*] Retrieving endpoint list from 10.129.14.128
Found domain(s):
 . DEVSMB
 . Builtin
[*] Looking up users in domain DEVSMB
Found user: mrb3n, uid = 1000
Found user: cry0l1t3, uid = 1001
mrb3n (1000)/FullName: 
mrb3n (1000)/UserComment: 
mrb3n (1000)/PrimaryGroupId: 513
mrb3n (1000)/BadPasswordCount: 0
mrb3n (1000)/LogonCount: 0
mrb3n (1000)/PasswordLastSet: 2021-09-22 17:47:59
mrb3n (1000)/PasswordDoesNotExpire: False
mrb3n (1000)/AccountIsDisabled: False
mrb3n (1000)/ScriptPath: 
cry0l1t3 (1001)/FullName: cry0l1t3
cry0l1t3 (1001)/UserComment: 
cry0l1t3 (1001)/PrimaryGroupId: 513
cry0l1t3 (1001)/BadPasswordCount: 0
cry0l1t3 (1001)/LogonCount: 0
cry0l1t3 (1001)/PasswordLastSet: 2021-09-22 17:50:56
cry0l1t3 (1001)/PasswordDoesNotExpire: False
cry0l1t3 (1001)/AccountIsDisabled: False
cry0l1t3 (1001)/ScriptPath: 
[*] Received 2 entries.

rpcclient로 얻은 정보는 SMBMap 혹은 CrackMapExec 도구로도 얻을 수 있음

SMBmap

realblackcat@htb[/htb]$ smbmap -H 10.129.14.128

[+] Finding open SMB ports....
[+] User SMB session established on 10.129.14.128...
[+] IP: 10.129.14.128:445       Name: 10.129.14.128                                     
        Disk                                                    Permissions     Comment
        ----                                                    -----------     -------
        print$                                                  NO ACCESS       Printer Drivers
        home                                                    NO ACCESS       INFREIGHT Samba
        dev                                                     NO ACCESS       DEVenv
        notes                                                   NO ACCESS       CheckIT
        IPC$                                                    NO ACCESS       IPC Service (DEVSM)

CrackMapExec

realblackcat@htb[/htb]$ crackmapexec smb 10.129.14.128 --shares -u '' -p ''

SMB         10.129.14.128   445    DEVSMB           [*] Windows 6.1 Build 0 (name:DEVSMB) (domain:) (signing:False) (SMBv1:False)
SMB         10.129.14.128   445    DEVSMB           [+] \: 
SMB         10.129.14.128   445    DEVSMB           [+] Enumerated shares
SMB         10.129.14.128   445    DEVSMB           Share           Permissions     Remark
SMB         10.129.14.128   445    DEVSMB           -----           -----------     ------
SMB         10.129.14.128   445    DEVSMB           print$                          Printer Drivers
SMB         10.129.14.128   445    DEVSMB           home                            INFREIGHT Samba
SMB         10.129.14.128   445    DEVSMB           dev                             DEVenv
SMB         10.129.14.128   445    DEVSMB           notes           READ,WRITE      CheckIT
SMB         10.129.14.128   445    DEVSMB           IPC$                            IPC Service (DEVSM)

또 다른 도구로는 enum4linux-ng가 있음. 이 도구는 전부는 아니지만 많은 쿼리를 자동화하며 많은 양의 정보를 반환할 수 있음

Enum4Linux-ng-열거형

realblackcat@htb[/htb]$ enum4linux-ng 10.129.14.128 -A

ENUM4LINUX - next generation

 ==========================
|    Target Information    |
 ==========================
[*] Target ........... 10.129.14.128
[*] Username ......... ''
[*] Random Username .. 'juzgtcsu'
[*] Password ......... ''
[*] Timeout .......... 5 second(s)

 =====================================
|    Service Scan on 10.129.14.128    |
 =====================================
[*] Checking LDAP
[-] Could not connect to LDAP on 389/tcp: connection refused
[*] Checking LDAPS
[-] Could not connect to LDAPS on 636/tcp: connection refused
[*] Checking SMB
[+] SMB is accessible on 445/tcp
[*] Checking SMB over NetBIOS
[+] SMB over NetBIOS is accessible on 139/tcp

 =====================================================
|    NetBIOS Names and Workgroup for 10.129.14.128    |
 =====================================================
[+] Got domain/workgroup name: DEVOPS
[+] Full NetBIOS names information:
- DEVSMB          <00> -         H <ACTIVE>  Workstation Service
- DEVSMB          <03> -         H <ACTIVE>  Messenger Service
- DEVSMB          <20> -         H <ACTIVE>  File Server Service
- ..__MSBROWSE__. <01> - <GROUP> H <ACTIVE>  Master Browser
- DEVOPS          <00> - <GROUP> H <ACTIVE>  Domain/Workgroup Name
- DEVOPS          <1d> -         H <ACTIVE>  Master Browser
- DEVOPS          <1e> - <GROUP> H <ACTIVE>  Browser Service Elections
- MAC Address = 00-00-00-00-00-00

 ==========================================
|    SMB Dialect Check on 10.129.14.128    |
 ==========================================
[*] Trying on 445/tcp
[+] Supported dialects and settings:
SMB 1.0: false
SMB 2.02: true
SMB 2.1: true
SMB 3.0: true
SMB1 only: false
Preferred dialect: SMB 3.0
SMB signing required: false

 ==========================================
|    RPC Session Check on 10.129.14.128    |
 ==========================================
[*] Check for null session
[+] Server allows session using username '', password ''
[*] Check for random user session
[+] Server allows session using username 'juzgtcsu', password ''
[H] Rerunning enumeration with user 'juzgtcsu' might give more results

 ====================================================
|    Domain Information via RPC for 10.129.14.128    |
 ====================================================
[+] Domain: DEVOPS
[+] SID: NULL SID
[+] Host is part of a workgroup (not a domain)

 ============================================================
|    Domain Information via SMB session for 10.129.14.128    |
 ============================================================
[*] Enumerating via unauthenticated SMB session on 445/tcp
[+] Found domain information via SMB
NetBIOS computer name: DEVSMB
NetBIOS domain name: ''
DNS domain: ''
FQDN: htb

 ================================================
|    OS Information via RPC for 10.129.14.128    |
 ================================================
[*] Enumerating via unauthenticated SMB session on 445/tcp
[+] Found OS information via SMB
[*] Enumerating via 'srvinfo'
[+] Found OS information via 'srvinfo'
[+] After merging OS information we have the following result:
OS: Windows 7, Windows Server 2008 R2
OS version: '6.1'
OS release: ''
OS build: '0'
Native OS: not supported
Native LAN manager: not supported
Platform id: '500'
Server type: '0x809a03'
Server type string: Wk Sv PrQ Unx NT SNT DEVSM

 ======================================
|    Users via RPC on 10.129.14.128    |
 ======================================
[*] Enumerating users via 'querydispinfo'
[+] Found 2 users via 'querydispinfo'
[*] Enumerating users via 'enumdomusers'
[+] Found 2 users via 'enumdomusers'
[+] After merging user results we have 2 users total:
'1000':
  username: mrb3n
  name: ''
  acb: '0x00000010'
  description: ''
'1001':
  username: cry0l1t3
  name: cry0l1t3
  acb: '0x00000014'
  description: ''

 =======================================
|    Groups via RPC on 10.129.14.128    |
 =======================================
[*] Enumerating local groups
[+] Found 0 group(s) via 'enumalsgroups domain'
[*] Enumerating builtin groups
[+] Found 0 group(s) via 'enumalsgroups builtin'
[*] Enumerating domain groups
[+] Found 0 group(s) via 'enumdomgroups'

 =======================================
|    Shares via RPC on 10.129.14.128    |
 =======================================
[*] Enumerating shares
[+] Found 5 share(s):
IPC$:
  comment: IPC Service (DEVSM)
  type: IPC
dev:
  comment: DEVenv
  type: Disk
home:
  comment: INFREIGHT Samba
  type: Disk
notes:
  comment: CheckIT
  type: Disk
print$:
  comment: Printer Drivers
  type: Disk
[*] Testing share IPC$
[-] Could not check share: STATUS_OBJECT_NAME_NOT_FOUND
[*] Testing share dev
[-] Share doesnt exist
[*] Testing share home
[+] Mapping: OK, Listing: OK
[*] Testing share notes
[+] Mapping: OK, Listing: OK
[*] Testing share print$
[+] Mapping: DENIED, Listing: N/A

 ==========================================
|    Policies via RPC for 10.129.14.128    |
 ==========================================
[*] Trying port 445/tcp
[+] Found policy:
domain_password_information:
  pw_history_length: None
  min_pw_length: 5
  min_pw_age: none
  max_pw_age: 49710 days 6 hours 21 minutes
  pw_properties:
  - DOMAIN_PASSWORD_COMPLEX: false
  - DOMAIN_PASSWORD_NO_ANON_CHANGE: false
  - DOMAIN_PASSWORD_NO_CLEAR_CHANGE: false
  - DOMAIN_PASSWORD_LOCKOUT_ADMINS: false
  - DOMAIN_PASSWORD_PASSWORD_STORE_CLEARTEXT: false
  - DOMAIN_PASSWORD_REFUSE_PASSWORD_CHANGE: false
domain_lockout_information:
  lockout_observation_window: 30 minutes
  lockout_duration: 30 minutes
  lockout_threshold: None
domain_logoff_information:
  force_logoff_time: 49710 days 6 hours 21 minutes

 ==========================================
|    Printers via RPC for 10.129.14.128    |
 ==========================================
[+] No printers returned (this is not an error)

Completed after 0.61 seconds

열거를 위해 두 개 이상의 도구를 사용해야 함. 도구의 프로그래밍으로 인해 수동으로 확인해야 하는 다른 정보를 얻을 수 있기 때문 -> 따라서 도구가 어떻게 작성되었는지 정확히 알 수 없는 자동화된 도구(autorecon 같은)에만 의존해선 안됨

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Last updated 1 year ago