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T1407 Download New Code at Runtime

Adversaries may download and execute dynamic code not included in the original application package after installation. This technique is primarily used to evade static analysis checks and pre-publication scans in official app stores. In some cases, more advanced dynamic or behavioral analysis techniques could detect this behavior. However, in conjunction with Execution Guardrails techniques, detecting malicious code downloaded after installation could be difficult.

On Android, dynamic code could include native code, Dalvik code, or JavaScript code that utilizes Android WebView’s JavascriptInterface capability.

On iOS, dynamic code could be downloaded and executed through 3rd party libraries such as JSPatch. 1

Item Value
ID T1407
Sub-techniques
Tactics TA0030
Platforms Android, iOS
Version 1.4
Created 25 October 2017
Last Modified 20 March 2023

Procedure Examples

ID Name Description
S1061 AbstractEmu AbstractEmu can download and install additional malware after initial infection.33
S0422 Anubis Anubis can download attacker-specified APK files.31
S0293 BrainTest Original samples of BrainTest download their exploit packs for rooting from a remote server after installation.14
S0432 Bread Bread has utilized JavaScript within WebViews that loaded a URL hosted on a Bread-controlled server which provided functions to run. Bread downloads billing fraud execution steps at runtime.13
S0655 BusyGasper BusyGasper can download a payload or updates from either its C2 server or email attachments in the adversary’s inbox.8
S0529 CarbonSteal CarbonSteal can dynamically load additional functionality.16
S0480 Cerberus Cerberus can update the malicious payload module on command.21
S0555 CHEMISTGAMES CHEMISTGAMES can download new modules while running.6
S0505 Desert Scorpion Desert Scorpion has been distributed in multiple stages.11
S0550 DoubleAgent DoubleAgent has downloaded additional code to root devices, such as TowelRoot.16
S0420 Dvmap Dvmap can download code and binaries from the C2 server to execute on the device as root.29
S0507 eSurv eSurv’s Android version is distributed in three stages: the dropper, the second stage payload, and the third stage payload which is Exodus.23
S0478 EventBot EventBot can download new libraries when instructed to.15
S0405 Exodus Exodus One, after checking in, sends a POST request and then downloads Exodus Two, the second stage binaries.27
S0577 FrozenCell FrozenCell has downloaded and installed additional applications.18
S0535 Golden Cup Golden Cup has been distributed in two stages.3
S0551 GoldenEagle GoldenEagle can download new code to update itself.16
S0536 GPlayed GPlayed has the capability to remotely load plugins and download and compile new .NET code.25
S0544 HenBox HenBox can load additional Dalvik code while running.9
S0325 Judy Judy bypasses Google Play’s protections by downloading a malicious payload at runtime after installation.12
S0485 Mandrake Mandrake can download its second (Loader) and third (Core) stages after the dropper is installed.17
S0295 RCSAndroid RCSAndroid has the ability to dynamically download and execute new code at runtime.30
S0539 Red Alert 2.0 Red Alert 2.0 can download additional overlay templates.32
S1055 SharkBot SharkBot can use the Android “Direct Reply” feature to spread the malware to other devices. It can also download the full version of the malware after initial device compromise.7
S0549 SilkBean SilkBean can install new applications which are obtained from the C2 server.16
S0327 Skygofree Skygofree can download executable code from the C2 server after the implant starts or after a specific command.22
S0324 SpyDealer SpyDealer downloads and executes root exploits from a remote server.10
S0545 TERRACOTTA TERRACOTTA can download additional modules at runtime via JavaScript eval statements.24
S0424 Triada Triada utilizes a backdoor in a Play Store app to install additional trojanized apps from the Command and Control server.20
S0506 ViperRAT ViperRAT has been installed in two stages and can secretly install new applications.28
G0112 Windshift Windshift has included malware functionality capable of downloading new DEX files at runtime during Operation BULL.34
S0489 WolfRAT WolfRAT can update the running malware.26
S0311 YiSpecter YiSpecter has used private APIs to download and install other pieces of itself, as well as other malicious apps. 4
S0494 Zen Zen can dynamically load executable code from remote sources.19
S0287 ZergHelper ZergHelper attempts to extend its capabilities via dynamic updating of its code.5

Mitigations

ID Mitigation Description
M1006 Use Recent OS Version Applications that target Android API level 29 or higher cannot execute native code stored in the application’s internal data storage directory, limiting the ability of applications to download and execute native code at runtime. 2

Detection

ID Data Source Data Component
DS0041 Application Vetting API Calls
DS0029 Network Traffic Network Traffic Content

References

  1. Jing Xie, Zhaofeng Chen, Jimmy Su. (2016, January 27). HOT OR NOT? THE BENEFITS AND RISKS OF IOS REMOTE HOT PATCHING. Retrieved December 9, 2016. ↩

  2. Android Developers. (n.d.). Behavior changes: all apps - Removed execute permission for app home directory. Retrieved September 20, 2019. ↩

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

  4. Claud Xiao. (2015, October 4). YiSpecter: First iOS Malware That Attacks Non-jailbroken Apple iOS Devices by Abusing Private APIs. Retrieved March 3, 2023. ↩

  5. Claud Xiao. (2016, February 21). Pirated iOS App Store’s Client Successfully Evaded Apple iOS Code Review. Retrieved December 12, 2016. ↩

  6. B. Leonard, N. Mehta. (2019, November 21). The Secret Life of Sandworms. Retrieved December 31, 2020. ↩

  7. RIFT: Research and Intelligence Fusion Team. (2022, March 3). SharkBot: a “new” generation Android banking Trojan being distributed on Google Play Store. Retrieved January 18, 2023. ↩

  8. Alexey Firsh. (2018, August 29). BusyGasper – the unfriendly spy. Retrieved October 1, 2021. ↩

  9. A. Hinchliffe, M. Harbison, J. Miller-Osborn, et al. (2018, March 13). HenBox: The Chickens Come Home to Roost. Retrieved September 9, 2019. ↩

  10. Wenjun Hu, Cong Zheng and Zhi Xu. (2017, July 6). SpyDealer: Android Trojan Spying on More Than 40 Apps. Retrieved September 18, 2018. ↩

  11. 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. ↩

  12. CheckPoint. (2017, May 25). The Judy Malware: Possibly the largest malware campaign found on Google Play. Retrieved September 18, 2018. ↩

  13. A. Guertin, V. Kotov, Android Security & Privacy Team. (2020, January 9). PHA Family Highlights: Bread (and Friends) . Retrieved April 27, 2020. ↩

  14. Chris Dehghanpoor. (2016, January 6). Brain Test re-emerges: 13 apps found in Google Play Read more: Brain Test re-emerges: 13 apps found in Google Play. Retrieved December 21, 2016. ↩

  15. D. Frank, L. Rochberger, Y. Rimmer, A. Dahan. (2020, April 30). EventBot: A New Mobile Banking Trojan is Born. Retrieved June 26, 2020. ↩

  16. 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. ↩↩↩↩

  17. R. Gevers, M. Tivadar, R. Bleotu, A. M. Barbatei, et al.. (2020, May 14). Uprooting Mandrake: The Story of an Advanced Android Spyware Framework That Went Undetected for 4 Years. Retrieved July 15, 2020. ↩

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

  19. Siewierski, L. (2019, January 11). PHA Family Highlights: Zen and its cousins . Retrieved July 27, 2020. ↩

  20. Lukasz Siewierski. (2019, June 6). PHA Family Highlights: Triada. Retrieved July 16, 2019. ↩

  21. Threat Fabric. (2019, August). Cerberus - A new banking Trojan from the underworld. Retrieved June 26, 2020. ↩

  22. Nikita Buchka and Alexey Firsh. (2018, January 16). Skygofree: Following in the footsteps of HackingTeam. Retrieved September 24, 2018. ↩

  23. A. Bauer. (2019, April 8). Lookout discovers phishing sites distributing new iOS and Android surveillanceware. Retrieved September 11, 2020. ↩

  24. Satori Threat Intelligence and Research Team. (2020, August). TERRACOTTA Android Malware: A Technical Study. Retrieved December 18, 2020. ↩

  25. V. Ventura. (2018, October 11). GPlayed Trojan - .Net playing with Google Market . Retrieved November 24, 2020. ↩

  26. W. Mercer, P. Rascagneres, V. Ventura. (2020, May 19). The wolf is back… . Retrieved July 20, 2020. ↩

  27. Security Without Borders. (2019, March 29). Exodus: New Android Spyware Made in Italy. Retrieved September 3, 2019. ↩

  28. M. Flossman. (2017, February 16). ViperRAT: The mobile APT targeting the Israeli Defense Force that should be on your radar. Retrieved September 11, 2020. ↩

  29. R. Unuchek. (2017, June 8). Dvmap: the first Android malware with code injection. Retrieved December 10, 2019. ↩

  30. Veo Zhang. (2015, July 21). Hacking Team RCSAndroid Spying Tool Listens to Calls; Roots Devices to Get In. Retrieved December 22, 2016. ↩

  31. K. Sun. (2019, January 17). Google Play Apps Drop Anubis, Use Motion-based Evasion. Retrieved January 20, 2021. ↩

  32. J. Chandraiah. (2018, July 23). Red Alert 2.0: Android Trojan targets security-seekers. Retrieved December 14, 2020. ↩

  33. P Shunk, K Balaam. (2021, October 28). Rooting Malware Makes a Comeback: Lookout Discovers Global Campaign. Retrieved February 6, 2023. ↩

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