tar is a command-line archiving tool used to create, list, extract and update archive files. It bundles multiple files and directories into one archive, usually preserving paths, permissions and timestamps, and is commonly paired with compression tools for distribution or backup.
What the tar command does
tar is a Unix-style archiving utility, so its core job is to package files and directories into a single archive for transfer, backup, or later extraction. It is often paired with compression tools, but tar itself is primarily about bundling and restoring file sets while preserving path structure and file metadata.
That distinction matters because tar is not a file viewer or a general-purpose compressor. The archive format is designed to keep related content together in a predictable way, which makes it useful for software distribution, system backups, and offline transport where directory layout and permissions need to survive the move.
How tar archives are structured
A tar archive is a sequential container of file entries and directory entries rather than a randomly addressable database-like format. Each entry carries path information and, depending on how it was created, may also preserve timestamps, permissions, ownership metadata, and symbolic link information.
Because of that structure, tar is efficient for streaming and simple to automate. You can write an archive to standard output, read one from standard input, or process large collections without needing a complex index. The trade-off is that tar is best suited to whole-archive operations, not selective editing of individual files inside the archive.
Common operational use cases
Administrators and developers use tar to package source trees, application bundles, log sets, and backup snapshots into a single file for transport or retention. In practice, it often sits in shell pipelines with gzip, bzip2, xz, or similar tools so the archive can be compressed after packaging.
Tar is also useful when the receiving system needs to reconstruct a directory tree exactly as it existed on the source system. That makes it a practical choice for reproducible deployment artifacts and file-level backups, especially when permissions, relative paths, and directory hierarchy are part of the expected result.
Security and integrity considerations
The main security issue with tar is not the command itself, but what is stored in the archive and where it is extracted. Archive contents can include unexpected absolute paths, parent-directory traversal sequences, or overwrite-prone filenames, so extraction should always be treated as a trust decision rather than a mechanical step.
Archive handling also affects integrity and availability. A corrupted or malicious archive can fail at extraction time, overwrite files in the wrong location, or hide unwanted content inside a legitimate-looking package. For that reason, tar workflows should be paired with source verification, controlled extraction paths, and review of archive contents before unpacking.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
MITRE ATT&CK addresses the attack and risk surface, while CIS Controls v8 and NIST SP 800-53 Rev 5 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| MITRE ATT&CK | T1560 — Archive Collected Data | tar directly supports archiving and packaging data for transfer or staging. |
| Recommendation — Monitor archive creation and use T1560 to investigate suspicious bundling of collected data. | ||
| CIS Controls v8 | CIS-10 — Data Recovery | tar is commonly used for backup archives and recovery workflows. |
| Recommendation — Use CIS-10 to protect tar-based backup archives and verify recoverability. | ||
| NIST SP 800-53 Rev 5 | SI-3 — Malicious Code Protection | tar archives can carry unsafe payloads that should be inspected before extraction. |
| CM-5 — Access Restrictions for Change | tar extraction can overwrite system files or alter protected content if misused. | |
| Recommendation — Apply SI-3 to scan archive contents before extraction from untrusted sources. Apply CM-5 to restrict who can write archive contents into protected locations. | ||
Practitioner Guidance
Why practitioners should care: Tar is simple, but it often appears in backup, deployment, and incident-response workflows where a mistake can affect many files at once. Treat archive creation and extraction as controlled operations, especially when archives come from external or untrusted sources.
What to watch for: Pay attention to path names, ownership metadata, and the extraction destination, because those details determine whether a tar archive restores cleanly or writes files somewhere unintended. For operational safety, inspect the archive contents before extraction when the source is not fully trusted.