type: attack-pattern
spec_version: 2.1
id: attack-pattern--fbd91bfc-75c2-4f0c-8116-3b4e722906b3
created: 2025-03-04T18:29:33.850Z
created_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
revoked: no
external_references: source_name: mitre-attack
url: https://attack.mitre.org/techniques/T1027/015
external_id: T1027.015
source_name: Perception Point
description: Arthur Vaiselbuh, Peleg Cabra. (2024, November 7). Evasive ZIP Concatenation: Trojan Targets Windows Users. Retrieved March 3, 2025.
url: https://perception-point.io/blog/evasive-concatenated-zip-trojan-targets-windows-users/
source_name: NTT Security Flagpro new December 2021
description: Hada, H. (2021, December 28). Flagpro The new malware used by BlackTech. Retrieved March 25, 2022.
url: https://insight-jp.nttsecurity.com/post/102hf3q/flagpro-the-new-malware-used-by-blacktech
source_name: The Hacker News
description: Ravie Lakshmanan. (2023, April 5). Hackers Using Self-Extracting Archives Exploit for Stealthy Backdoor Attacks. Retrieved March 3, 2025.
url: https://thehackernews.com/2023/04/hackers-using-self-extracting-archives.html
source_name: Trustwave Pillowmint June 2020
description: Trustwave SpiderLabs. (2020, June 22). Pillowmint: FIN7’s Monkey Thief . Retrieved July 27, 2020.
url: https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/pillowmint-fin7s-monkey-thief/
object_marking_refs: marking-definition--fa42a846-8d90-4e51-bc29-71d5b4802168
modified: 2025-04-15T19:59:24.125Z
name: Compression
description: Adversaries may use compression to obfuscate their payloads or files. Compressed file formats such as ZIP, gzip, 7z, and RAR can compress and archive multiple files together to make it easier and faster to transfer files. In addition to compressing files, adversaries may also compress shellcode directly - for example, in order to store it in a Windows Registry key (i.e., [Fileless Storage](https://attack.mitre.org/techniques/T1027/011)).(Citation: Trustwave Pillowmint June 2020)

In order to further evade detection, adversaries may combine multiple ZIP files into one archive. This process of concatenation creates an archive that appears to be a single archive but in fact contains the central directories of the embedded archives. Some ZIP readers, such as 7zip, may not be able to identify concatenated ZIP files and miss the presence of the malicious payload.(Citation: Perception Point)

File archives may be sent as one [Spearphishing Attachment](https://attack.mitre.org/techniques/T1566/001) through email. Adversaries have sent malicious payloads as archived files to encourage the user to interact with and extract the malicious payload onto their system (i.e., [Malicious File](https://attack.mitre.org/techniques/T1204/002)).(Citation: NTT Security Flagpro new December 2021) However, some file compression tools, such as 7zip, can be used to produce self-extracting archives. Adversaries may send self-extracting archives to hide the functionality of their payload and launch it without requiring multiple actions from the user.(Citation: The Hacker News)

[Compression](https://attack.mitre.org/techniques/T1027/015) may be used in combination with [Encrypted/Encoded File](https://attack.mitre.org/techniques/T1027/013) where compressed files are encrypted and password-protected.
kill_chain_phases: kill_chain_name: mitre-attack
phase_name: defense-evasion
x_mitre_attack_spec_version: 3.2.0
x_mitre_contributors: Fernando Bacchin
x_mitre_deprecated: no
x_mitre_domains: enterprise-attack
x_mitre_is_subtechnique: yes
x_mitre_modified_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
x_mitre_platforms: Linux
Windows
macOS
x_mitre_version: 1.0