T1521.002: Asymmetric Cryptography
Adversaries may employ a known asymmetric encryption algorithm to conceal command and control traffic, rather than relying on any inherent protections provided by a communication protocol. Asymmetric cryptography, also known as public key cryptography, uses a keypair per party: one public that can be freely distributed, and one private that should not be distributed. Due to how asymmetric algorithms work, the sender encrypts data with the receiver’s public key and the receiver decrypts the data with their private key. This ensures that only the intended recipient can read the encrypted data. Common public key encryption algorithms include RSA, ElGamal, and ECDSA.
For efficiency, many protocols (including SSL/TLS) use symmetric cryptography once a connection is established, but use asymmetric cryptography to establish or transmit a key. As such, these protocols are classified as Asymmetric Cryptography.
Security context for executives and security teams
T1521.002: Asymmetric Cryptography describes Adversaries may employ a known asymmetric encryption algorithm to conceal command and control traffic, rather than relying on any inherent protections provided by a communication protocol. Asymmetric cryptography, also known as public key cryptography, uses a keypair per party: one public that can be freely distributed, and one private that should not be distributed. Due to how asymmetric algorithms work, the sender encrypts data with the receiver’s public key and the receiver decrypts the data with their private k...
Executive priority
T1521.002: Asymmetric Cryptography is an official MITRE ATT&CK technique. Glexia treats it as defensive behavior context for prioritizing monitoring, control validation, and response planning without using the object by itself as an attribution claim.
Technical view
Security teams should validate T1521.002: Asymmetric Cryptography by reviewing the official ATT&CK relationships, mapped tactics (command-and-control), supported platforms (Android, iOS), and available local telemetry before making detection or mitigation decisions.
Likely telemetry
- Official ATT&CK relationships and object metadata
Detection direction
- Validate whether T1521.002: Asymmetric Cryptography appears in your detection coverage and tabletop scenarios.
- Use the object to align executive risk language with SOC, incident response, and detection engineering work.
- Do not treat ATT&CK relationship context as attribution without corroborating evidence.
Mitigation priorities
- Map the object to existing controls and identify missing telemetry or response ownership.
- Prioritize mitigations that reduce exposure on the listed platforms and tactics.
- Review adjacent ATT&CK relationships before changing policy, detections, or reporting language.
Additional notes and limits
Baseline Glexia take generated from the official MITRE ATT&CK STIX object, source hash, tactics, platforms, and detection fields. It is safe to replace with a richer model-generated take for the same source hash later.
This baseline take is source-grounded and schema-validated, but it does not include environment-specific telemetry, incident evidence, or threat-intelligence corroboration.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Asymmetric Cryptography
Adversaries may employ a known asymmetric encryption algorithm to conceal command and control traffic, rather than relying on any inherent protections provided by a communication protocol. Asymmetric cryptography, also known as public key cryptography, uses a keypair per party: one public that can be freely distributed, and one private that should not be distributed. Due to how asymmetric algorithms work, the sender encrypts data with the receiver’s public key and the receiver decrypts the data with their private key. This ensures that only the intended recipient can read the encrypted data. Common public key encryption algorithms include RSA, ElGamal, and ECDSA.
For efficiency, many protocols (including SSL/TLS) use symmetric cryptography once a connection is established, but use asymmetric cryptography to establish or transmit a key. As such, these protocols are classified as Asymmetric Cryptography.
How security teams should use this page
Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.
Related techniques
This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.
| Domain | ID | Name | Relationship / procedure |
|---|---|---|---|
| Mobile | T1521 | Encrypted Channel | This object subtechnique of Encrypted Channel. |
Groups, software, and campaigns
S0529: CarbonSteal
CarbonSteal is one of a family of four surveillanceware tools that share a common C2 infrastructure. CarbonSteal primarily deals with audio surveillance. [1]
S1216: TriangleDB
TriangleDB is an Objective-C written implant deployed after Binary Validator and after root privileges are obtained during Operation Triangulation’s infection chain. Upon execution, TriangleDB communicates with the C2 server, relaying information about the victim device.[1]
S0507: eSurv
S1055: SharkBot
S0555: CHEMISTGAMES
CHEMISTGAMES is a modular backdoor that has been deployed by Sandworm Team.[1]
S0549: SilkBean
S1067: FluBot
FluBot is a multi-purpose mobile banking malware that was first observed in Spain in late 2020. It primarily spread through European countries using a variety of SMS phishing messages in multiple languages.[1][2] An international law enforcement operation of 11 countries eventually disrupted the spread of FluBot.[3]
C0054: Operation Triangulation
Operation Triangulation is a mobile campaign targeting iOS devices.[1] The unidentified actors used zero-click exploits in iMessage attachments to gain Initial Access, then executed exploits and validators, such as Binary Validator before finally executing the TriangleDB implant.
All related ATT&CK context
Object version and sync metadata
The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates.
Imported snapshots across ATT&CK releases(2)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 19.2 | 1.0 | Current bundle | 2e52721b0195… | ||
| 19.1 | 1.0 | Older bundle | 2e52721b0195… |
Mirrored ATT&CK source object
The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.
External references and citations
MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.
- [1]mitre-attackT1521.002Open source URL
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