Web Service: Dead Drop Resolver

Adversaries may use an existing, legitimate external Web service to host information that points to additional command and control (C2) infrastructure. Adversaries may post content, known as a dead drop resolver, on Web services with embedded (and often obfuscated/encoded) domains or IP addresses. Once infected, victims will reach out to and be redirected by these resolvers.

Popular websites and social media acting as a mechanism for C2 may give a significant amount of cover due to the likelihood that hosts within a network are already communicating with them prior to a compromise. Using common services, such as those offered by Google or Twitter, makes it easier for adversaries to hide in expected noise. Web service providers commonly use SSL/TLS encryption, giving adversaries an added level of protection.

Use of a dead drop resolver may also protect back-end C2 infrastructure from discovery through malware binary analysis while also enabling operational resiliency (since this infrastructure may be dynamically changed).

ID: T1102.001
Sub-technique of:  T1102
Platforms: Linux, Windows, macOS
Permissions Required: User
Version: 1.0
Created: 14 March 2020
Last Modified: 26 March 2020

Procedure Examples

ID Name Description
G0096 APT41

APT41 used legitimate websites for C2 through dead drop resolvers (DDR), including GitHub, Pastebin, and Microsoft TechNet.[1]

S0373 Astaroth

Astaroth can store C2 information on cloud hosting services such as AWS and CloudFlare and websites like YouTube and Facebook.[2]


BADNEWS collects C2 information via a dead drop resolver.[3][4][5]


BLACKCOFFEE uses Microsoft’s TechNet Web portal to obtain a dead drop resolver containing an encoded tag with the IP address of a command and control server.[6][7]


BRONZE BUTLER's MSGET downloader uses a dead drop resolver to access malicious payloads.[8]

C0017 C0017

During C0017, APT41 used dead drop resolvers on two separate tech community forums for their KEYPLUG Windows-version backdoor; notably APT41 updated the community forum posts frequently with new dead drop resolvers during the campaign.[9]

S0674 CharmPower

CharmPower can retrieve C2 domain information from actor-controlled S3 buckets.[10]

S0531 Grandoreiro

Grandoreiro can obtain C2 information from Google Docs.[2]

S0528 Javali

Javali can read C2 information from Google Documents and YouTube.[2]


The KEYPLUG Windows variant has retrieved C2 addresses from encoded data in posts on tech community forums.[9]

S0455 Metamorfo

Metamorfo has used YouTube to store and hide C&C server domains.[11]

S0051 MiniDuke

Some MiniDuke components use Twitter to initially obtain the address of a C2 server or as a backup if no hard-coded C2 server responds.[12][13][14]

G0040 Patchwork

Patchwork hides base64-encoded and encrypted C2 server locations in comments on legitimate websites.[15]

S0013 PlugX

PlugX uses Pastebin to store C2 addresses.[16]

S0518 PolyglotDuke

PolyglotDuke can use Twitter, Reddit, Imgur and other websites to get a C2 URL.[14]

G0106 Rocke

Rocke has used Pastebin to check the version of beaconing malware and redirect to another Pastebin hosting updated malware.[17]

S0148 RTM

RTM has used an RSS feed on Livejournal to update a list of encrypted C2 server names. RTM has also hidden Pony C2 server IP addresses within transactions on the Bitcoin and Namecoin blockchain.[18][19][20]

G0048 RTM

RTM has used an RSS feed on Livejournal to update a list of encrypted C2 server names.[18]

S0341 Xbash

Xbash can obtain a webpage hosted on Pastebin to update its C2 domain list.[21]


ID Mitigation Description
M1031 Network Intrusion Prevention

Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary malware can be used to mitigate activity at the network level.

M1021 Restrict Web-Based Content

Web proxies can be used to enforce external network communication policy that prevents use of unauthorized external services.


ID Data Source Data Component Detects
DS0029 Network Traffic Network Traffic Content

Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).

Network Traffic Flow

Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.


  1. Fraser, N., et al. (2019, August 7). Double DragonAPT41, a dual espionage and cyber crime operation APT41. Retrieved September 23, 2019.
  2. GReAT. (2020, July 14). The Tetrade: Brazilian banking malware goes global. Retrieved November 9, 2020.
  3. Settle, A., et al. (2016, August 8). MONSOON - Analysis Of An APT Campaign. Retrieved September 22, 2016.
  4. Levene, B. et al.. (2018, March 7). Patchwork Continues to Deliver BADNEWS to the Indian Subcontinent. Retrieved March 31, 2018.
  5. Lunghi, D., et al. (2017, December). Untangling the Patchwork Cyberespionage Group. Retrieved July 10, 2018.
  6. FireEye Labs/FireEye Threat Intelligence. (2015, May 14). Hiding in Plain Sight: FireEye and Microsoft Expose Obfuscation Tactic. Retrieved January 22, 2016.
  7. FireEye. (2018, March 16). Suspected Chinese Cyber Espionage Group (TEMP.Periscope) Targeting U.S. Engineering and Maritime Industries. Retrieved April 11, 2018.
  8. Counter Threat Unit Research Team. (2017, October 12). BRONZE BUTLER Targets Japanese Enterprises. Retrieved January 4, 2018.
  9. Rufus Brown, Van Ta, Douglas Bienstock, Geoff Ackerman, John Wolfram. (2022, March 8). Does This Look Infected? A Summary of APT41 Targeting U.S. State Governments. Retrieved July 8, 2022.
  10. Check Point. (2022, January 11). APT35 exploits Log4j vulnerability to distribute new modular PowerShell toolkit. Retrieved January 24, 2022.
  11. ESET Research. (2019, October 3). Casbaneiro: peculiarities of this banking Trojan that affects Brazil and Mexico. Retrieved September 23, 2021.