Taint Shared Content
Adversaries may deliver payloads to remote systems by adding content to shared storage locations, such as network drives or internal code repositories. Content stored on network drives or in other shared locations may be tainted by adding malicious programs, scripts, or exploit code to otherwise valid files. Once a user opens the shared tainted content, the malicious portion can be executed to run the adversary's code on a remote system. Adversaries may use tainted shared content to move laterally. A directory share pivot is a variation on this technique that uses several other techniques to propagate malware when users access a shared network directory. It uses Shortcut Modification of directory .LNK files that use Masquerading to look like the real directories, which are hidden through Hidden Files and Directories. The malicious .LNK-based directories have an embedded command that executes the hidden malware file in the directory and then opens the real intended directory so that the user's expected action still occurs. When used with frequently used network directories, the technique may result in frequent reinfections and broad access to systems and potentially to new and higher privileged accounts. (Citation: Retwin Directory Share Pivot) Adversaries may also compromise shared network directories through binary infections by appending or prepending its code to the healthy binary on the shared network directory. The malware may modify the original entry point (OEP) of the healthy binary to ensure that it is executed before the legitimate code. The infection could continue to spread via the newly infected file when it is executed by a remote system. These infections may target both binary and non-binary formats that end with extensions including, but not limited to, .EXE, .DLL, .SCR, .BAT, and/or .VBS.
Procedure Examples |
|
| Name | Description |
|---|---|
| H1N1 |
H1N1 has functionality to copy itself to network shares.(Citation: Cisco H1N1 Part 2) |
| Darkhotel |
Darkhotel used a virus that propagates by infecting executables stored on shared drives.(Citation: Kaspersky Darkhotel) |
| Ramsay |
Ramsay can spread itself by infecting other portable executable files on networks shared drives.(Citation: Eset Ramsay May 2020) |
| Gamaredon Group |
Gamaredon Group has injected malicious macros into all Word and Excel documents on mapped network drives.(Citation: ESET Gamaredon June 2020) |
| BRONZE BUTLER |
BRONZE BUTLER has placed malware on file shares and given it the same name as legitimate documents on the share.(Citation: Secureworks BRONZE BUTLER Oct 2017) |
| InvisiMole |
InvisiMole can replace legitimate software or documents in the compromised network with their trojanized versions, in an attempt to propagate itself within the network.(Citation: ESET InvisiMole June 2020) |
| Conti |
Conti can spread itself by infecting other remote machines via network shared drives.(Citation: Cybereason Conti Jan 2021)(Citation: CarbonBlack Conti July 2020) |
| Miner-C |
Miner-C copies itself into the public folder of Network Attached Storage (NAS) devices and infects new victims who open the file.(Citation: Softpedia MinerC) |
| Stuxnet |
Stuxnet infects remote servers via network shares and by infecting WinCC database views with malicious code.(Citation: Symantec W.32 Stuxnet Dossier) |
| Ursnif |
Ursnif has copied itself to and infected files in network drives for propagation.(Citation: TrendMicro Ursnif Mar 2015)(Citation: TrendMicro Ursnif File Dec 2014) |
Mitigations |
|
| Mitigation | Description |
|---|---|
| Taint Shared Content Mitigation |
Protect shared folders by minimizing users who have write access. Use utilities that detect or mitigate common features used in exploitation, such as the Microsoft Enhanced Mitigation Experience Toolkit (EMET). Reduce potential lateral movement risk by using web-based document management and collaboration services that do not use network file and directory sharing. Identify potentially malicious software that may be used to taint content or may result from it and audit and/or block the unknown programs by using whitelisting (Citation: Beechey 2010) tools, like AppLocker, (Citation: Windows Commands JPCERT) (Citation: NSA MS AppLocker) or Software Restriction Policies (Citation: Corio 2008) where appropriate. (Citation: TechNet Applocker vs SRP) |
| Execution Prevention |
Block execution of code on a system through application control, and/or script blocking. |
| Restrict File and Directory Permissions |
Restrict access by setting directory and file permissions that are not specific to users or privileged accounts. |
| Exploit Protection |
Use capabilities to detect and block conditions that may lead to or be indicative of a software exploit occurring. |
Detection
Processes that write or overwrite many files to a network shared directory may be suspicious. Monitor processes that are executed from removable media for malicious or abnormal activity such as network connections due to Command and Control and possible network Discovery techniques. Frequently scan shared network directories for malicious files, hidden files, .LNK files, and other file types that may not typical exist in directories used to share specific types of content.
References
- Routin, D. (2017, November 13). Abusing network shares for efficient lateral movements and privesc (DirSharePivot). Retrieved April 12, 2018.
- Kaspersky Lab's Global Research and Analysis Team. (2014, November). The Darkhotel APT A Story of Unusual Hospitality. Retrieved November 12, 2014.
- Nicolas Falliere, Liam O. Murchu, Eric Chien. (2011, February). W32.Stuxnet Dossier. Retrieved December 7, 2020.
- Caragay, R. (2014, December 11). Info-Stealing File Infector Hits US, UK. Retrieved June 5, 2019.
- Caragay, R. (2015, March 26). URSNIF: The Multifaceted Malware. Retrieved June 5, 2019.
- Boutin, J. (2020, June 11). Gamaredon group grows its game. Retrieved June 16, 2020.
- Cimpanu, C.. (2016, September 9). Cryptocurrency Mining Malware Discovered Targeting Seagate NAS Hard Drives. Retrieved October 12, 2016.
- Reynolds, J.. (2016, September 14). H1N1: Technical analysis reveals new capabilities – part 2. Retrieved September 26, 2016.
- Sanmillan, I.. (2020, May 13). Ramsay: A cyber‑espionage toolkit tailored for air‑gapped networks. Retrieved May 27, 2020.
- Microsoft. (2012, June 27). Using Software Restriction Policies and AppLocker Policies. Retrieved April 7, 2016.
- Corio, C., & Sayana, D. P. (2008, June). Application Lockdown with Software Restriction Policies. Retrieved November 18, 2014.
- NSA Information Assurance Directorate. (2014, August). Application Whitelisting Using Microsoft AppLocker. Retrieved March 31, 2016.
- Tomonaga, S. (2016, January 26). Windows Commands Abused by Attackers. Retrieved February 2, 2016.
- Beechey, J. (2010, December). Application Whitelisting: Panacea or Propaganda?. Retrieved November 18, 2014.
- Counter Threat Unit Research Team. (2017, October 12). BRONZE BUTLER Targets Japanese Enterprises. Retrieved January 4, 2018.
- Baskin, B. (2020, July 8). TAU Threat Discovery: Conti Ransomware. Retrieved February 17, 2021.
- Rochberger, L. (2021, January 12). Cybereason vs. Conti Ransomware. Retrieved February 17, 2021.
- Hromcova, Z. and Cherpanov, A. (2020, June). INVISIMOLE: THE HIDDEN PART OF THE STORY. Retrieved July 16, 2020.
Связанные риски
| Риск | Связи | |
|---|---|---|
|
Боковое перемещение злоумышленника по локальной сети из-за
возможно добавления ВПО в ярлыки и файлы общих сетевых ресурсов в файловых службах и службы хранилища
Конфиденциальность
Целостность
|
|
Каталоги
Мы используем cookie-файлы, чтобы получить статистику, которая помогает нам улучшить сервис для вас с целью персонализации сервисов и предложений. Вы может прочитать подробнее о cookie-файлах или изменить настройки браузера. Продолжая пользоваться сайтом, вы даёте согласие на использование ваших cookie-файлов и соглашаетесь с Политикой обработки персональных данных.