CMMC Practice Number: SI.L1-3.14.5
CMMC Level: 1 CMMC Domain: System and Information Integrity (SI)
Practice Summary:
Perform periodic scans of the information system and real-time scans of files from external sources as files are downloaded, opened, or executed.
Contents:
CMMC Practice Implementation |
Assessment Objectives
Determine if:
[a] the frequency for malicious code scans is defined;
[b] malicious code scans are performed with the defined frequency; and
[c] real-time malicious code scans of files from external sources as files are downloaded, opened, or executed are performed.
Practice Clarification (DOD, CMU)
Use anti-malware software to scan for and identify viruses in your computer systems and determine how often scans are conducted [a]. Real-time scans look at the system whenever new files are downloaded, opened, and saved [c]. Periodic scans check previously saved files against updated malware information [b].
Example
You work with your company’s email provider to enable enhanced protections that will scan all attachments to identify and quarantine those that may be harmful prior to a user opening them [c]. In addition, you configure antivirus software on each computer and to scan for malicious code every day [a,b]. The software also scans files that are downloaded or copied from removable media such as USB drives. It quarantines any suspicious files and notifies the security team [c].
Potential Assessment Considerations
• Are files from media (e.g., USB drives, CD-ROM) included in the definition of external sources and are they being scanned [c]?
Where To Look
- System and information integrity policy
- configuration management policy and procedures
- procedures addressing malicious code protection
- malicious code protection mechanisms
- records of malicious code protection updates
- system security plan
- system design documentation
- system configuration settings and associated documentation
- scan results from malicious code protection mechanisms
- record of actions initiated by malicious code protection mechanisms in response to malicious code detection
- system audit logs and records
- other relevant documents or records
Who To Talk To
- System or network administrators
- personnel with information security responsibilities
- personnel installing, configuring, and maintaining the system
- personnel with responsibility for malicious code protection
- personnel with configuration management responsibility
Perform Test On
- Organizational processes for employing, updating, and configuring malicious code protection mechanisms
- organizational process for addressing false positives and resulting potential impact
- mechanisms supporting or implementing malicious code protection mechanisms (including updates and configurations)
- mechanisms supporting or implementing malicious code scanning and subsequent actions
Additional Information
Malicious code protection mechanisms include anti-virus signature definitions and reputation-based technologies. Many technologies and methods exist to limit or eliminate the effects of malicious code. Pervasive configuration management and comprehensive software integrity controls may be effective in preventing execution of unauthorized code. In addition to commercial off-the-shelf software, malicious code may also be present in custom-built software. This could include logic bombs, back doors, and other types of cyber- attacks that could affect organizational missions/business functions. Traditional malicious code protection mechanisms cannot always detect such code. In these situations, organizations rely instead on other safeguards including secure coding practices, configuration management and control, trusted procurement processes, and monitoring practices to help ensure that software does not perform functions other than the functions intended.
CMMC Practice Background and References (DOD, CMU) |
Practice Discussion:
DISCUSSION FROM SOURCE: NIST SP 800-171 R2
Periodic scans of organizational systems and real-time scans of files from external sources can detect malicious code. Malicious code can be encoded in various formats (e.g., UUENCODE, Unicode), contained within compressed or hidden files, or hidden in files using techniques such as steganography. Malicious code can be inserted into systems in a variety of ways including web accesses, electronic mail, electronic mail attachments, and portable storage devices. Malicious code insertions occur through the exploitation of system vulnerabilities.
CMMC References:
· FAR Clause 52.204-21 b.1.xv
· NIST SP 800-171 Rev 1 3.14.5
· CIS Controls v7.1 8.4, 8.7
· NIST CSF v1.1 DE.CM-4
· CERT RMM v1.2 VAR:SG3.SP1
· NIST SP 800-53 Rev 4 SI-3