telnet.exe

  • File Path: C:\windows\system32\telnet.exe
  • Description: Microsoft Telnet Client

Hashes

Type Hash
MD5 1964C1DAF256B7B67CC613B8A75223D8
SHA1 ED7751FE31E12B14511B07CF4906A21B81831D1F
SHA256 7A1C7D7B5C77789106EA4FFD398A132825C6C97B69957D76719FF64B34628DF9
SHA384 FF631BAA71488E50FB872D91C47D78956A179CEA2E955E47B9857DAF24D829C6E8C4951BD93DEEC42176D34DEA616B97
SHA512 586CCB9678556808E3E2930C5F4CAAD5058363366D84D133C1B733D9D9B6FE38D5C397A6D350E7F4711B9A6BB5D08E8479E2DCCC0530DA3A79E94F0BF84BF5C6
SSDEEP 3072:X/CN6vRPAnyYmmhhtqPQMMaUvaJpoqrdNotXeaBo:PCNWqnrmoLpac8nrSB

Signature

  • Status: The file C:\windows\system32\telnet.exe is not digitally signed. You cannot run this script on the current system. For more information about running scripts and setting execution policy, see about_Execution_Policies at http://go.microsoft.com/fwlink/?LinkID=135170
  • Serial: ``
  • Thumbprint: ``
  • Issuer:
  • Subject:

File Metadata

  • Original Filename: telnetc.exe.mui
  • Product Name: Microsoft Windows Operating System
  • Company Name: Microsoft Corporation
  • File Version: 6.3.9600.16384 (winblue_rtm.130821-1623)
  • Product Version: 6.3.9600.16384
  • Language: English (United States)
  • Legal Copyright: Microsoft Corporation. All rights reserved.

Possible Misuse

The following table contains possible examples of telnet.exe being misused. While telnet.exe is not inherently malicious, its legitimate functionality can be abused for malicious purposes.

Source Source File Example License
sigma lnx_auditd_network_service_scanning.yml - '/telnet' DRL 1.0
sigma lnx_apt_equationgroup_lnx.yml - '/bin/telnet locip locport < /dev/console \| /bin/sh' DRL 1.0
sigma lnx_apt_equationgroup_lnx.yml - '&& telnet * 2>&1 </dev/console' DRL 1.0
sigma lnx_shell_susp_rev_shells.yml - ' \| /bin/bash \| telnet ' DRL 1.0
sigma proc_creation_macos_network_service_scanning.yml - '/telnet' DRL 1.0
sigma proc_creation_lnx_network_service_scanning.yml - '/telnet' # could be wget, curl, ssh, many things. basically everything that is able to do network connection. consider fine tuning DRL 1.0
sigma image_load_uac_bypass_via_dism.yml - Actions of a legitimate telnet client DRL 1.0
sigma proc_creation_win_multiple_suspicious_cli.yml - telnet.exe DRL 1.0
sigma proc_creation_win_susp_plink_remote_forward.yml Description: 'Command-line SSH, Telnet, and Rlogin client' DRL 1.0
malware-ioc LinuxMooseETrules.txt alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET TROJAN Possible Linux/Moose Telnet CnC Beacon"; flow:established,to_server; dsize:40; content:"\|0e 00 00 00\|"; offset:4; depth:4; fast_pattern; content:!"\|00\|"; within:1; content:!"\|00\|"; distance:3; within:1; content:"\|00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\|"; distance:4; within:28; content:!"\|00 00 00 00\|"; depth:4; reference:url,welivesecurity.com/wp-content/uploads/2015/05/Dissecting-LinuxMoose.pdf; classtype:trojan-activity; sid:2021149; rev:1;) © ESET 2014-2018
malware-ioc moose leveraging weak or default usernames and passwords via the Telnet protocol. If © ESET 2014-2018
atomic-red-team T1046.md Upon successful execution, sh will utilize nmap, telnet, and nc to contact a single or range of adresseses on port 80 to determine if listening. Results will be via stdout. MIT License. © 2018 Red Canary
atomic-red-team T1046.md telnet #{host} #{port} MIT License. © 2018 Red Canary
atomic-red-team T1046.md ##### Description: Check if telnet command exists on the machine MIT License. © 2018 Red Canary
atomic-red-team T1046.md if [ -x “$(command -v telnet)” ]; then exit 0; else exit 1; fi; MIT License. © 2018 Red Canary
atomic-red-team T1046.md (which yum && yum -y install epel-release telnet)||(which apt-get && DEBIAN_FRONTEND=noninteractive apt-get install -y telnet) MIT License. © 2018 Red Canary
atomic-red-team T1110.001.md * Telnet (23/TCP) MIT License. © 2018 Red Canary
atomic-red-team T1110.003.md * Telnet (23/TCP) MIT License. © 2018 Red Canary
atomic-red-team T1110.004.md * Telnet (23/TCP) MIT License. © 2018 Red Canary
atomic-red-team T1571.md Testing uncommonly used port utilizing PowerShell. APT33 has been known to attempt telnet over port 8081. Upon execution, details about the successful MIT License. © 2018 Red Canary
atomic-red-team T1571.md Testing uncommonly used port utilizing telnet. MIT License. © 2018 Red Canary
atomic-red-team T1571.md telnet #{domain} #{port} MIT License. © 2018 Red Canary
signature-base apt_eqgrp.yar $x5 = “-p DEST_PORT, –dest_port=DEST_PORT defaults: telnet=23, ssh=22 (optional) - Change to LOCAL redirect port” fullword ascii CC BY-NC 4.0
signature-base apt_eqgrp.yar description = “EQGRP Toolset Firewall - from files ssh.py, telnet.py” CC BY-NC 4.0
signature-base apt_eqgrp_apr17.yar $s2 = “Cut and paste the following to the telnet prompt:” fullword ascii CC BY-NC 4.0
signature-base apt_eqgrp_apr17.yar description = “Equation Group hack tool leaked by ShadowBrokers- file wrap-telnet.sh” CC BY-NC 4.0
signature-base apt_eqgrp_apr17.yar $x2 = “Remote Usage: /bin/telnet locip locport < /dev/console | /bin/sh"” fullword ascii CC BY-NC 4.0
signature-base apt_fvey_shadowbroker_dec16.yar $s5 = “bll.telnet” fullword ascii CC BY-NC 4.0
signature-base apt_fvey_shadowbroker_dec16.yar $s1 = “/sbin/sh -c (mkdir /tmp/.X11R6; cd /tmp/.X11R6 && telnet” ascii CC BY-NC 4.0
signature-base generic_anomalies.yar $s1 = “SSH, Telnet and Rlogin client” fullword wide CC BY-NC 4.0
signature-base thor-hacktools.yar description = “Disclosed hacktool set (old stuff) - file TELNET.EXE from Windows ME” CC BY-NC 4.0
signature-base thor-hacktools.yar $s0 = “TELNET [host [port]]” fullword wide CC BY-NC 4.0
signature-base thor-hacktools.yar $s2 = “TELNET.EXE” fullword wide CC BY-NC 4.0
signature-base thor-hacktools.yar $s14 = “Software\Microsoft\Telnet” fullword wide CC BY-NC 4.0
signature-base thor-hacktools.yar description = “Detects malicious telnet shell” CC BY-NC 4.0
signature-base thor-webshells.yar description = “Semi-Auto-generated - file telnet.pl.txt” CC BY-NC 4.0
signature-base thor-webshells.yar description = “Semi-Auto-generated - file telnet.cgi.txt” CC BY-NC 4.0

Additional Info*

*The information below is copied from MicrosoftDocs, which is maintained by Microsoft. Available under CC BY 4.0 license.


telnet

Applies to: Windows Server 2022, Windows Server 2019, Windows Server 2016, Windows Server 2012 R2, Windows Server 2012

Communicates with a computer running the telnet server service. Running this command without any parameters, lets you enter the telnet context, as indicated by the telnet prompt (Microsoft telnet>). From the telnet prompt, you can use telnet commands to manage the computer running the telnet client.

[!IMPORTANT] You must install the telnet client software before you can run this command. For more information, see Installing telnet.

Syntax

telnet [/a] [/e <escapechar>] [/f <filename>] [/l <username>] [/t {vt100 | vt52 | ansi | vtnt}] [<host> [<port>]] [/?]

Parameters

Parameter Description
/a Attempts automatic logon. Same as /l option, except that it uses the currently logged on user’s name.
/e <escapechar> Specifies the escape character used to enter the telnet client prompt.
/f <filename> Specifies the file name used for client side logging.
/l <username> Specifies the user name to log on with on the remote computer.
/t {vt100 | vt52 | ansi | vtnt} Specifies the terminal type. Supported terminal types are vt100, vt52, ansi, and vtnt.
<host> [<port>] Specifies the hostname or IP address of the remote computer to connect to, and optionally the TCP port to use (default is TCP port 23).
/? Displays help at the command prompt.

Examples

To use telnet to connect to the computer running the telnet Server Service at telnet.microsoft.com, type:

telnet telnet.microsoft.com

To use telnet to connect to the computer running the telnet Server Service at telnet.microsoft.com on TCP port 44 and ro log the session activity in a local file called telnetlog.txt, type:

telnet /f telnetlog.txt telnet.microsoft.com 44

Additional References


MIT License. Copyright (c) 2020-2021 Strontic.