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T1420 File and Directory Discovery

Adversaries may enumerate files and directories or search in specific device locations for desired information within a filesystem. Adversaries may use the information from File and Directory Discovery during automated discovery to shape follow-on behaviors, including deciding if the adversary should fully infect the target and/or attempt specific actions.

On Android, Linux file permissions and SELinux policies typically stringently restrict what can be accessed by apps without taking advantage of a privilege escalation exploit. The contents of the external storage directory are generally visible, which could present concerns if sensitive data is inappropriately stored there. iOS’s security architecture generally restricts the ability to perform any type of File and Directory Discovery without use of escalated privileges.

Item Value
ID T1420
Sub-techniques
Tactics TA0032
Platforms Android, iOS
Version 1.2
Created 25 October 2017
Last Modified 20 March 2023

Procedure Examples

ID Name Description
S0529 CarbonSteal CarbonSteal has searched device storage for various files, including .amr files (audio recordings) and superuser binaries.4
S0505 Desert Scorpion Desert Scorpion can list files stored on external storage.5
S0550 DoubleAgent DoubleAgent has searched for specific existing data directories, including the Gmail app, Dropbox app, Pictures, and thumbnails.4
S0577 FrozenCell FrozenCell has searched for pdf, doc, docx, ppt, pptx, xls, and xlsx file types for exfiltration.2
S0535 Golden Cup Golden Cup can collect a directory listing of external storage.3
S0551 GoldenEagle GoldenEagle has looked for .doc, .txt, .gif, .apk, .jpg, .png, .mp3, and .db files on external storage.4
C0016 Operation Dust Storm During Operation Dust Storm, the threat actors used Android backdoors capable of enumerating specific files on the infected devices.7
S0549 SilkBean SilkBean can get file lists on the SD card.4
S0558 Tiktok Pro Tiktok Pro can list all hidden files in the /DCIM/.dat/ directory.1
G0112 Windshift Windshift has included file enumeration in the malicious apps deployed as part of Operation BULL and Operation ROCK.6

Mitigations

ID Mitigation Description
M1006 Use Recent OS Version Security architecture improvements in each new version of Android and iOS make it more difficult to escalate privileges. Additionally, newer versions of Android have strengthened the sandboxing applied to applications, restricting their ability to enumerate file system contents.

Detection

ID Data Source Data Component
DS0042 User Interface Permissions Request

References

  1. S. Desai. (2020, September 8). TikTok Spyware. Retrieved January 5, 2021. ↩

  2. Michael Flossman. (2017, October 5). FrozenCell: Multi-platform surveillance campaign against Palestinians. Retrieved November 11, 2020. ↩

  3. R. Iarchy, E. Rynkowski. (2018, July 5). GoldenCup: New Cyber Threat Targeting World Cup Fans. Retrieved October 29, 2020. ↩

  4. A. Kumar, K. Del Rosso, J. Albrecht, C. Hebeisen. (2020, June 1). Mobile APT Surveillance Campaigns Targeting Uyghurs - A collection of long-running Android tooling connected to a Chinese mAPT actor. Retrieved November 10, 2020. ↩↩↩↩

  5. A. Blaich, M. Flossman. (2018, April 16). Lookout finds new surveillanceware in Google Play with ties to known threat actor targeting the Middle East. Retrieved September 11, 2020. ↩

  6. The BlackBerry Research & Intelligence Team. (2020, October). BAHAMUT: Hack-for-Hire Masters of Phishing, Fake News, and Fake Apps. Retrieved February 8, 2021. ↩

  7. Gross, J. (2016, February 23). Operation Dust Storm. Retrieved December 22, 2021. ↩