Command and Scripting Interpreter
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries. These interfaces and languages provide ways of interacting with computer systems and are a common feature across many different platforms. Most systems come with some built-in command-line interface and scripting capabilities, for example, macOS and Linux distributions include some flavor of Unix Shell while Windows installations include the Windows Command Shell and PowerShell.
Adversaries may abuse these technologies in various ways as a means of executing arbitrary commands. Commands and scripts can be embedded in Initial Access payloads delivered to victims as lure documents or as secondary payloads downloaded from an existing C2. Adversaries may also execute commands through interactive terminals/shells.
Anti-virus can be used to automatically quarantine suspicious files.
Where possible, only permit execution of signed scripts.
|Disable or Remove Feature or Program||
Disable or remove any unnecessary or unused shells or interpreters.
Use application control where appropriate.
|Privileged Account Management||
When PowerShell is necessary, restrict PowerShell execution policy to administrators. Be aware that there are methods of bypassing the PowerShell execution policy, depending on environment configuration.
|Restrict Web-Based Content||
Script blocking extensions can help prevent the execution of scripts and HTA files that may commonly be used during the exploitation process. For malicious code served up through ads, adblockers can help prevent that code from executing in the first place.
Command-line and scripting activities can be captured through proper logging of process execution with command-line arguments. This information can be useful in gaining additional insight to adversaries' actions through how they use native processes or custom tools. Also monitor for loading of modules associated with specific languages.
If scripting is restricted for normal users, then any attempt to enable scripts running on a system would be considered suspicious. If scripts are not commonly used on a system, but enabled, scripts running out of cycle from patching or other administrator functions are suspicious. Scripts should be captured from the file system when possible to determine their actions and intent.
Scripts are likely to perform actions with various effects on a system that may generate events, depending on the types of monitoring used. Monitor processes and command-line arguments for script execution and subsequent behavior. Actions may be related to network and system information discovery, collection, or other scriptable post-compromise behaviors and could be used as indicators of detection leading back to the source script.
- Sutherland, S. (2014, September 9). 15 Ways to Bypass the PowerShell Execution Policy. Retrieved July 23, 2015.
- Schroeder, W., Warner, J., Nelson, M. (n.d.). Github PowerShellEmpire. Retrieved April 28, 2016.
- QiAnXin Threat Intelligence Center. (2019, February 18). APT-C-36: Continuous Attacks Targeting Colombian Government Institutions and Corporations. Retrieved May 5, 2020.
- FireEye. (2018, February 20). APT37 (Reaper): The Overlooked North Korean Actor. Retrieved March 1, 2018.
- Alperovitch, D.. (2016, June 15). Bears in the Midst: Intrusion into the Democratic National Committee. Retrieved August 3, 2016.
- ESET. (2016, October). En Route with Sednit - Part 2: Observing the Comings and Goings. Retrieved November 21, 2016.
- FireEye Threat Intelligence. (2015, July 13). Demonstrating Hustle, Chinese APT Groups Quickly Use Zero-Day Vulnerability (CVE-2015-5119) Following Hacking Team Leak. Retrieved January 25, 2016.
- Pantazopoulos, N. (2018, April 17). Decoding network data from a Gh0st RAT variant. Retrieved November 2, 2018.
- ClearSky Cyber Security and Trend Micro. (2017, July). Operation Wilted Tulip: Exposing a cyber espionage apparatus. Retrieved August 21, 2017.
- Kujawa, A. (2018, March 27). You dirty RAT! Part 1: DarkComet. Retrieved November 6, 2018.
- Ebach, L. (2017, June 22). Analysis Results of Zeus.Variant.Panda. Retrieved November 5, 2018.
- Check Point Research. (2019, February 4). SpeakUp: A New Undetected Backdoor Linux Trojan. Retrieved April 17, 2019.
- Schwarz, D. et al. (2019, October 16). TA505 Distributes New SDBbot Remote Access Trojan with Get2 Downloader. Retrieved May 29, 2020.
- US-CERT. (2018, March 16). Alert (TA18-074A): Russian Government Cyber Activity Targeting Energy and Other Critical Infrastructure Sectors. Retrieved June 6, 2018.
- Marczak, B. and Scott-Railton, J.. (2016, May 29). Keep Calm and (Don’t) Enable Macros: A New Threat Actor Targets UAE Dissidents. Retrieved June 8, 2016.
- Sardiwal, M, et al. (2017, December 7). New Targeted Attack in the Middle East by APT34, a Suspected Iranian Threat Group, Using CVE-2017-11882 Exploit. Retrieved December 20, 2017.
- Falcone, R. and Lee, B. (2017, July 27). OilRig Uses ISMDoor Variant; Possibly Linked to Greenbug Threat Group. Retrieved January 8, 2018.
- Lee, B., Falcone, R. (2018, February 23). OopsIE! OilRig Uses ThreeDollars to Deliver New Trojan. Retrieved July 16, 2018.
- Lee, B., Falcone, R. (2018, July 25). OilRig Targets Technology Service Provider and Government Agency with QUADAGENT. Retrieved August 9, 2018.
- Falcone, R., Wilhoit, K.. (2018, November 16). Analyzing OilRig’s Ops Tempo from Testing to Weaponization to Delivery. Retrieved April 23, 2019.
- Villeneuve, N., Bennett, J. T., Moran, N., Haq, T., Scott, M., & Geers, K. (2014). OPERATION “KE3CHANG”: Targeted Attacks Against Ministries of Foreign Affairs. Retrieved November 12, 2014.
- Smallridge, R. (2018, March 10). APT15 is alive and strong: An analysis of RoyalCli and RoyalDNS. Retrieved April 4, 2018.
- Ahl, I. (2017, June 06). Privileges and Credentials: Phished at the Request of Counsel. Retrieved May 17, 2018.
- Carr, N., et al. (2018, August 01). On the Hunt for FIN7: Pursuing an Enigmatic and Evasive Global Criminal Operation. Retrieved August 23, 2018.
- Platt, J. and Reeves, J.. (2019, March). FIN7 Revisited: Inside Astra Panel and SQLRat Malware. Retrieved June 18, 2019.
- FireEye Threat Intelligence. (2016, April). Follow the Money: Dissecting the Operations of the Cyber Crime Group FIN6. Retrieved June 1, 2016.
- McKeague, B. et al. (2019, April 5). Pick-Six: Intercepting a FIN6 Intrusion, an Actor Recently Tied to Ryuk and LockerGoga Ransomware. Retrieved April 17, 2019.
- Bromiley, M. and Lewis, P. (2016, October 7). Attacking the Hospitality and Gaming Industries: Tracking an Attacker Around the World in 7 Years. Retrieved October 6, 2017.
- Symantec. (2019, March 6). Whitefly: Espionage Group has Singapore in Its Sights. Retrieved May 26, 2020.
- GReAT. (2019, April 10). Gaza Cybergang Group1, operation SneakyPastes. Retrieved May 13, 2020.
- Dahan, A. (2017). Operation Cobalt Kitty. Retrieved December 27, 2018.