Query: SIEM correlation: credential access activity consistent with Multi-Factor Authentication Interception
Matching passage: T1111 Multi-Factor Authentication Interception. Tactics: credential access. Description: Adversaries may target multi-factor authentication (MFA) mechanisms, (i.e., smart cards, token generators, etc.) to gain access to credentials that can be used to access systems, services, and network resources. Use of MFA is recommended and provides a higher level of security than usernames and passwords alone, but organizations should be aware of techniques that could be used to intercept and bypass these security mechanisms. If a smart card is used for multi-factor authentication, then a keylogger will need to be used to obtain the password associated with a smart card during normal use. With both an inserted card and access to the smart card password, an adversary can connect to a network resource using the infected system to proxy the authentication with the inserted hardware token. (Citation: Mandiant M Trends 2011) Adversaries may also employ a keylogger to similarly target other hardware tokens, such as RSA SecurID. Capturing token input (including a user's personal identification code) may provide temporary access (i.e. replay the one-time passcode until the next value rollover) as well as possibly enabling adversaries to reliably predict future authentication values (given access to both the algorithm and any seed values used to generate appended temporary codes). (Citation: GCN RSA June 2011) Other methods of MFA may be intercepted and used by an adversary to authenticate. It is common for one-time codes to be sent via out-of-band communications (email, SMS). If the device and/or service is not secured, then it may be vulnerable to interception. Service providers can also be targeted: for example, an adversary may compromise an SMS messaging service in order to steal MFA codes sent to users’ phones.(Citation: Okta Scatter Swine 2022)
Near-miss passage: T1558.005 Ccache Files. Tactics: credential access. Description: Adversaries may attempt to steal Kerberos tickets stored in credential cache files (or ccache). These files are used for short term storage of a user's active session credentials. The ccache file is created upon user authentication and allows for access to multiple services without the user having to re-enter credentials. The <code>/etc/krb5.conf</code> configuration file and the <code>KRB5CCNAME</code> environment variable are used to set the storage location for ccache entries. On Linux, credentials are typically stored in the `/tmp` directory with a naming format of `krb5cc_%UID%` or `krb5.ccache`. On macOS, ccache entries are stored by default in memory with an `API:{uuid}` naming scheme. Typically, users interact with ticket storage using <code>kinit</code>, which obtains a Ticket-Granting-Ticket (TGT) for the principal; <code>klist</code>, which lists obtained tickets currently held in the credentials cache; and other built-in binaries.(Citation: Kerberos GNU/Linux)(Citation: Binary Defense Kerberos Linux) Adversaries can collect tickets from ccache files stored on disk and authenticate as the current user without their password to perform [Pass the Ticket](https://attack.mitre.org/techniques/T1550/003) attacks. Adversaries can also use these tickets to impersonate legitimate users with elevated privileges to perform [Privilege Escalation](https://attack.mitre.org/tactics/TA0004). Tools like Kekeo can also be used by adversaries to convert ccache files to Windows format for further [Lateral Movement](https://attack.mitre.org/tactics/TA0008). On macOS, adversaries may use open-source tools or the Kerberos framework to interact with ccache files and extract TGTs or Service Tickets via lower-level APIs.(Citation: SpectorOps Bifrost Kerberos macOS 2019)(Citation: Linux Kerberos Tickets)(Citation: Brining MimiKatz to Unix)(Citation: Kekeo)