Credentials in Files
Adversaries may search local file systems and remote file shares for files containing passwords. These can be files created by users to store their own credentials, shared credential stores for a group of individuals, configuration files containing passwords for a system or service, or source code/binary files containing embedded passwords.
It is possible to extract passwords from backups or saved virtual machines through Credential Dumping.  Passwords may also be obtained from Group Policy Preferences stored on the Windows Domain Controller. 
|APT3||APT3 has a tool that can locate credentials in files on the file system such as those from Firefox or Chrome. |
|Azorult||Azorult can steal credentials in files belonging to common software such as Skype, Telegram, and Steam. |
|BlackEnergy||BlackEnergy has used a plug-in to gather credentials stored in files on the host by various software programs, including The Bat! email client, Outlook, and Windows Credential Store.  |
|Emotet||Emotet has been observed leveraging a module that retrieves passwords stored on a system for the current logged-on user.  |
|Empire||Empire can use various modules to search for files containing passwords. |
|jRAT||jRAT can capture passwords from common chat applications such as MSN Messenger, AOL, Instant Messenger, and and Google Talk. |
|LaZagne||LaZagne can obtain credentials from browsers, chats, databases, mail, and WiFi. |
|MuddyWater||MuddyWater has run a tool that steals passwords saved in victim email. |
|Olympic Destroyer||Olympic Destroyer contains a module that tries to obtain stored credentials from web browsers. |
|pngdowner||If an initial connectivity check fails, pngdowner attempts to extract proxy details and credentials from Windows Protected Storage and from the IE Credentials Store. This allows the adversary to use the proxy credentials for subsequent requests if they enable outbound HTTP access. |
|PoshC2||PoshC2 contains modules for searching for passwords in local and remote files. |
|Proton||Proton gathers credentials in files for 1password, and keychains. |
|QuasarRAT||QuasarRAT can obtain passwords from FTP clients.  |
|Smoke Loader||Smoke Loader searches for files named logins.json to parse for credentials. |
|Stolen Pencil||Stolen Pencil has used tools that are capable of obtaining credentials from saved mail. |
|TA505||TA505 has used malware to gather credentials from FTP clients and Outlook. |
|TrickBot||TrickBot can obtain passwords stored in files from several applications such as Outlook, Filezilla, and WinSCP. Additionally, it searches for the ".vnc.lnk" affix to steal VNC credentials.  |
|Turla||Turla has gathered credentials from the Windows Credential Manager tool. |
|XTunnel||XTunnel is capable of accessing locally stored passwords on victims. |
|Active Directory Configuration||Remove vulnerable Group Policy Preferences. |
|Audit||Preemptively search for files containing passwords and take actions to reduce the exposure risk when found.|
|Password Policies||Establish an organizational policy that prohibits password storage in files.|
|Restrict File and Directory Permissions||Restrict file shares to specific directories with access only to necessary users.|
|User Training||Ensure that developers and system administrators are aware of the risk associated with having plaintext passwords in software configuration files that may be left on endpoint systems or servers.|
While detecting adversaries accessing these files may be difficult without knowing they exist in the first place, it may be possible to detect adversary use of credentials they have obtained. Monitor the command-line arguments of executing processes for suspicious words or regular expressions that may indicate searching for a password (for example: password, pwd, login, secure, or credentials). See Valid Accounts for more information.
- CG. (2014, May 20). Mimikatz Against Virtual Machine Memory Part 1. Retrieved November 12, 2014.
- Security Research and Defense. (2014, May 13). MS14-025: An Update for Group Policy Preferences. Retrieved January 28, 2015.
- Microsoft. (2014, May 13). MS14-025: Vulnerability in Group Policy Preferences could allow elevation of privilege. Retrieved January 28, 2015.
- MaxXor. (n.d.). QuasarRAT. Retrieved July 10, 2018.
- Meltzer, M, et al. (2018, June 07). Patchwork APT Group Targets US Think Tanks. Retrieved July 16, 2018.
- Metcalf, S. (2015, November 13). Unofficial Guide to Mimikatz & Command Reference. Retrieved December 23, 2015.
- Grafnetter, M. (2015, October 26). Retrieving DPAPI Backup Keys from Active Directory. Retrieved December 19, 2017.
- Zanni, A. (n.d.). The LaZagne Project !!!. Retrieved December 14, 2018.
- Schroeder, W., Warner, J., Nelson, M. (n.d.). Github PowerShellEmpire. Retrieved April 28, 2016.
- Nettitude. (2016, June 8). PoshC2: Powershell C2 Server and Implants. Retrieved April 23, 2019.
- Belcher, P.. (2016, July 28). Tunnel of Gov: DNC Hack and the Russian XTunnel. Retrieved August 3, 2016.
- Yan, T., et al. (2018, November 21). New Wine in Old Bottle: New Azorult Variant Found in FindMyName Campaign using Fallout Exploit Kit. Retrieved November 29, 2018.
- Anthony, N., Pascual, C.. (2018, November 1). Trickbot Shows Off New Trick: Password Grabber Module. Retrieved November 16, 2018.
- Llimos, N., Pascual, C.. (2019, February 12). Trickbot Adds Remote Application Credential-Grabbing Capabilities to Its Repertoire. Retrieved March 12, 2019.
- F-Secure Labs. (2014). BlackEnergy & Quedagh: The convergence of crimeware and APT attacks. Retrieved March 24, 2016.
- Baumgartner, K. and Garnaeva, M.. (2014, November 3). BE2 custom plugins, router abuse, and target profiles. Retrieved March 24, 2016.
- Baker, B., Unterbrink H. (2018, July 03). Smoking Guns - Smoke Loader learned new tricks. Retrieved July 5, 2018.
- Patrick Wardle. (n.d.). Mac Malware of 2017. Retrieved September 21, 2018.
- Crowdstrike Global Intelligence Team. (2014, June 9). CrowdStrike Intelligence Report: Putter Panda. Retrieved January 22, 2016.
- Mercer, W. and Rascagneres, P. (2018, February 12). Olympic Destroyer Takes Aim At Winter Olympics. Retrieved March 14, 2019.
- US-CERT. (2018, July 20). Alert (TA18-201A) Emotet Malware. Retrieved March 25, 2019.
- CIS. (2018, December 12). MS-ISAC Security Primer- Emotet. Retrieved March 25, 2019.
- Kamluk, V. & Gostev, A. (2016, February). Adwind - A Cross-Platform RAT. Retrieved April 23, 2019.
- Symantec DeepSight Adversary Intelligence Team. (2018, December 10). Seedworm: Group Compromises Government Agencies, Oil & Gas, NGOs, Telecoms, and IT Firms. Retrieved December 14, 2018.
- Symantec Security Response. (2016, September 6). Buckeye cyberespionage group shifts gaze from US to Hong Kong. Retrieved September 26, 2016.
- ASERT team. (2018, December 5). STOLEN PENCIL Campaign Targets Academia. Retrieved February 5, 2019.
- Proofpoint Staff. (2017, September 27). Threat Actor Profile: TA505, From Dridex to GlobeImposter. Retrieved May 28, 2019.
- Symantec DeepSight Adversary Intelligence Team. (2019, June 20). Waterbug: Espionage Group Rolls Out Brand-New Toolset in Attacks Against Governments. Retrieved July 8, 2019.