数据加密以实现影响是攻击者通过加密关键数据破坏目标系统可用性的终极攻击手段,常见于勒索软件攻击链的最终阶段。传统检测方法主要依赖识别异常文件修改模式(如大规模文件重命名、加密头特征)、监控系统工具滥用(如vssadmin删除卷影副本)以及检测加密进程行为特征。防御方可通过文件完整性监控、存储快照保护和进程行为分析等手段进行缓解。
为对抗日益成熟的加密行为检测技术,攻击者发展出多维度的加密匿迹方法,通过动态算法混淆、进程上下文伪装、时空行为分散及云服务滥用等策略,将恶意加密操作深度嵌入系统正常业务流程,大幅降低加密行为的可观测性与可关联性。
当前数据加密匿迹技术的演进呈现三大共性特征:一是加密行为的上下文融合,通过劫持合法进程或云服务API,使恶意操作获得系统信任背书;二是加密特征的动态变异,采用算法轮换与参数随机化破坏静态特征检测;三是攻击节奏的智能控制,利用分阶段执行与条件触发机制规避突发行为检测。动态加密算法轮换技术通过密码学层面的持续变异,使得每次加密产生独特的特征指纹;合法进程注入加密则重构了恶意行为的进程上下文,将其伪装成用户或系统发起的正常操作;分阶段加密通过长周期行为稀释,规避基于短时间窗口的异常检测;云存储API滥用加密更是将攻击完全融入云平台安全体系,实现"以子之盾,陷子之矛"的对抗效果。这些技术共同构建了加密攻击的"合法化"执行环境,显著提升了防御方识别恶意加密行为的难度。
匿迹技术的发展迫使防御体系从单一特征检测转向多维度行为关联分析,需结合密码学特征动态解析、进程行为链追踪、云API调用上下文理解等新型检测能力,同时构建跨存储介质、跨时间维度的加密行为基线模型,才能有效应对隐蔽性不断增强的数据加密威胁。
| 效应类型 | 是否存在 |
|---|---|
| 特征伪装 | ✅ |
| 行为透明 | ✅ |
| 数据遮蔽 | ✅ |
| 时空释痕 | ✅ |
通过动态加密算法轮换和云存储API滥用,将恶意加密特征伪装成合规的数据保护操作。算法参数的持续变化使得加密流量无法形成稳定指纹,而云服务原生加密API的调用则使攻击行为获得平台合法性背书,有效混淆恶意加密与正常安全加固的界限。
合法进程注入加密技术通过深度寄生在系统可信进程中,使加密操作脱离独立恶意进程的可见范围。防御方难以在正常应用行为中区分出被注入的加密线程,导致加密行为在进程监控层面呈现透明化。
所有子技术均依赖高强度加密算法对数据进行不可逆混淆,符合数据遮蔽效应中"使防御者望不透"的核心特征。加密后的数据完全丧失可读性,且动态密钥管理机制确保无法通过密码分析恢复原始内容。
分阶段加密延迟触发技术将加密行为分散在长达数周的时间跨度中,同时结合目录随机遍历实现空间维度上的操作分散。这种长周期、低密度的攻击节奏将加密特征稀释在系统正常维护活动中,破坏防御方的时间关联分析能力。
| ID | Name | Description |
|---|---|---|
| S1129 | Akira |
Akira encrypts victim filesystems for financial extortion purposes.[1] |
| G1024 | Akira |
Akira encrypts files in victim environments as part of ransomware operations.[2] |
| S1133 | Apostle |
Apostle creates new, encrypted versions of files then deletes the originals, with the new filenames consisting of a random GUID and ".lock" for an extension.[3] |
| G0082 | APT38 |
APT38 has used Hermes ransomware to encrypt files with AES256.[4] |
| G0096 | APT41 |
APT41 used a ransomware called Encryptor RaaS to encrypt files on the targeted systems and provide a ransom note to the user.[5] APT41 also used Microsoft Bitlocker to encrypt workstations and Jetico’s BestCrypt to encrypt servers.[6] |
| S0640 | Avaddon |
Avaddon encrypts the victim system using a combination of AES256 and RSA encryption schemes.[7] |
| S1053 | AvosLocker |
AvosLocker has encrypted files and network resources using AES-256 and added an |
| S0638 | Babuk |
Babuk can use ChaCha8 and ECDH to encrypt data.[12][13][14][15] |
| S0606 | Bad Rabbit |
Bad Rabbit has encrypted files and disks using AES-128-CBC and RSA-2048.[16] |
| S0570 | BitPaymer |
BitPaymer can import a hard-coded RSA 1024-bit public key, generate a 128-bit RC4 key for each file, and encrypt the file in place, appending |
| S1070 | Black Basta |
Black Basta can encrypt files with the ChaCha20 cypher and using a multithreaded process to increase speed.[18][19][20][21][22][23][24][25][26] |
| S1068 | BlackCat |
BlackCat has the ability to encrypt Windows devices, Linux devices, and VMWare instances.[27] |
| C0015 | C0015 |
During C0015, the threat actors used Conti ransomware to encrypt a compromised network.[28] |
| C0018 | C0018 |
During C0018, the threat actors used AvosLocker ransomware to encrypt files on the compromised network.[10][29] |
| S1096 | Cheerscrypt |
Cheerscrypt can encrypt data on victim machines using a Sosemanuk stream cipher with an Elliptic-curve Diffie–Hellman (ECDH) generated key.[30][31] |
| S0611 | Clop |
Clop can encrypt files using AES, RSA, and RC4 and will add the ".clop" extension to encrypted files.[32][33][34] |
| S0575 | Conti |
Conti can use |
| S0625 | Cuba |
Cuba has the ability to encrypt system data and add the ".cuba" extension to encrypted files.[39] |
| S1111 | DarkGate | |
| S1033 | DCSrv |
DCSrv has encrypted drives using the core encryption mechanism from DiskCryptor.[41] |
| S0616 | DEATHRANSOM |
DEATHRANSOM can use public and private key pair encryption to encrypt files for ransom payment.[42] |
| S0659 | Diavol |
Diavol has encrypted files using an RSA key though the |
| S0554 | Egregor |
Egregor can encrypt all non-system files using a hybrid AES-RSA algorithm prior to displaying a ransom note.[44][45] |
| S0605 | EKANS |
EKANS uses standard encryption library functions to encrypt files.[46][47] |
| G0046 | FIN7 |
FIN7 has encrypted virtual disk volumes on ESXi servers using a version of Darkside ransomware.[48][49] |
| G0061 | FIN8 |
FIN8 has deployed ransomware such as Ragnar Locker, White Rabbit, and attempted to execute Noberus on compromised networks.[50] |
| S0618 | FIVEHANDS |
FIVEHANDS can use an embedded NTRU public key to encrypt data for ransom.[42][51][52] |
| S0617 | HELLOKITTY |
HELLOKITTY can use an embedded RSA-2048 public key to encrypt victim data for ransom.[42] |
| C0038 | HomeLand Justice |
During HomeLand Justice, threat actors used ROADSWEEP ransomware to encrypt files on targeted systems.[53][54][55] |
| G1032 | INC Ransom |
INC Ransom has used INC Ransomware to encrypt victim's data.[56][57][58][59][60][61] |
| S1139 | INC Ransomware |
INC Ransomware can encrypt data on victim systems, including through the use of partial encryption and multi-threading to speed encryption.[56][57][60][61][56] |
| G0119 | Indrik Spider |
Indrik Spider has encrypted domain-controlled systems using BitPaymer.[17] Additionally, Indrik Spider used PsExec to execute a ransomware script.[62] |
| S0389 | JCry |
JCry has encrypted files and demanded Bitcoin to decrypt those files. [63] |
| S0607 | KillDisk |
KillDisk has a ransomware component that encrypts files with an AES key that is also RSA-1028 encrypted.[64] |
| S0372 | LockerGoga |
LockerGoga has encrypted files, including core Windows OS files, using RSA-OAEP MGF1 and then demanded Bitcoin be paid for the decryption key.[65][66][67] |
| G0059 | Magic Hound |
Magic Hound has used BitLocker and DiskCryptor to encrypt targeted workstations. [68][69] |
| S0449 | Maze |
Maze has disrupted systems by encrypting files on targeted machines, claiming to decrypt files if a ransom payment is made. Maze has used the ChaCha algorithm, based on Salsa20, and an RSA algorithm to encrypt files.[70] |
| S0576 | MegaCortex |
MegaCortex has used the open-source library, Mbed Crypto, and generated AES keys to carry out the file encryption process.[71][72] |
| S1137 | Moneybird |
Moneybird targets a common set of file types such as documents, certificates, and database files for encryption while avoiding executable, dynamic linked libraries, and similar items.[73] |
| G1036 | Moonstone Sleet |
Moonstone Sleet has deployed ransomware in victim environments.[74] |
| S0457 | Netwalker |
Netwalker can encrypt files on infected machines to extort victims.[75] |
| S0368 | NotPetya |
NotPetya encrypts user files and disk structures like the MBR with 2048-bit RSA.[76][77][78] |
| S0556 | Pay2Key |
Pay2Key can encrypt data on victim's machines using RSA and AES algorithms in order to extort a ransom payment for decryption.[79][80] |
| S1162 | Playcrypt |
Playcrypt encrypts files on targeted hosts with an AES-RSA hybrid encryption, encrypting every other file portion of 0x100000 bytes.[81][82] |
| S1058 | Prestige |
Prestige has leveraged the CryptoPP C++ library to encrypt files on target systems using AES and appended filenames with |
| S0654 | ProLock |
ProLock can encrypt files on a compromised host with RC6, and encrypts the key with RSA-1024.[84] |
| S0583 | Pysa |
Pysa has used RSA and AES-CBC encryption algorithm to encrypt a list of targeted file extensions.[85] |
| S0481 | Ragnar Locker |
Ragnar Locker encrypts files on the local machine and mapped drives prior to displaying a note demanding a ransom.[86][87] |
| S0496 | REvil |
REvil can encrypt files on victim systems and demands a ransom to decrypt the files.[88][89][90][91][92][93][94][95] |
| S1150 | ROADSWEEP |
ROADSWEEP can RC4 encrypt content in blocks on targeted systems.[53][54][55] |
| S0400 | RobbinHood |
RobbinHood will search for an RSA encryption key and then perform its encryption process on the system files.[96] |
| S1073 | Royal |
Royal uses a multi-threaded encryption process that can partially encrypt targeted files with the OpenSSL library and the AES256 algorithm.[97][98][99] |
| S0446 | Ryuk |
Ryuk has used a combination of symmetric (AES) and asymmetric (RSA) encryption to encrypt files. Files have been encrypted with their own AES key and given a file extension of .RYK. Encrypted directories have had a ransom note of RyukReadMe.txt written to the directory.[100][38] |
| S0370 | SamSam |
SamSam encrypts victim files using RSA-2048 encryption and demands a ransom be paid in Bitcoin to decrypt those files.[101] |
| G0034 | Sandworm Team |
Sandworm Team has used Prestige ransomware to encrypt data at targeted organizations in transportation and related logistics industries in Ukraine and Poland.[83] |
| G1015 | Scattered Spider |
Scattered Spider has used BlackCat ransomware to encrypt files on VMWare ESXi servers.[102][103] |
| S0639 | Seth-Locker |
Seth-Locker can encrypt files on a targeted system, appending them with the suffix .seth.[15] |
| S0140 | Shamoon |
Shamoon has an operational mode for encrypting data instead of overwriting it.[104][105] |
| S0242 | SynAck |
SynAck encrypts the victims machine followed by asking the victim to pay a ransom. [106] |
| G0092 | TA505 |
TA505 has used a wide variety of ransomware, such as Clop, Locky, Jaff, Bart, Philadelphia, and GlobeImposter, to encrypt victim files and demand a ransom payment.[107] |
| S0595 | ThiefQuest |
ThiefQuest encrypts a set of file extensions on a host, deletes the original files, and provides a ransom note with no contact information.[108] |
| S0366 | WannaCry |
WannaCry encrypts user files and demands that a ransom be paid in Bitcoin to decrypt those files.[109][110][111] |
| S0612 | WastedLocker |
WastedLocker can encrypt data and leave a ransom note.[112][113][114] |
| S0341 | Xbash |
Xbash has maliciously encrypted victim's database systems and demanded a cryptocurrency ransom be paid.[115] |
| S0658 | XCSSET |
XCSSET performs AES-CBC encryption on files under |
| ID | Mitigation | Description |
|---|---|---|
| M1040 | Behavior Prevention on Endpoint |
On Windows 10, enable cloud-delivered protection and Attack Surface Reduction (ASR) rules to block the execution of files that resemble ransomware. [117] |
| M1053 | Data Backup |
Consider implementing IT disaster recovery plans that contain procedures for regularly taking and testing data backups that can be used to restore organizational data.[118] Ensure backups are stored off system and is protected from common methods adversaries may use to gain access and destroy the backups to prevent recovery. Consider enabling versioning in cloud environments to maintain backup copies of storage objects.[119] |
| ID | Data Source | Data Component | Detects |
|---|---|---|---|
| DS0010 | Cloud Storage | Cloud Storage Modification |
Monitor for changes made in cloud environments for events that indicate storage objects have been anomalously modified. |
| DS0017 | Command | Command Execution |
Monitor executed commands and arguments for actions involved in data destruction activity, such as vssadmin, wbadmin, and bcdedit |
| DS0022 | File | File Creation |
Monitor for newly constructed files in user directories. |
| File Modification |
Monitor for changes made to files in user directories. |
||
| DS0033 | Network Share | Network Share Access |
Monitor for unexpected network shares being accessed on target systems or on large numbers of systems. |
| DS0009 | Process | Process Creation |
Monitor for newly constructed processes and/or command-lines involved in data destruction activity, such as vssadmin, wbadmin, and bcdedit. |