#StopRansomware: Zeppelin Ransomware

Summary

Actions to take today to mitigate cyber threats from ransomware:

• Prioritize remediating known exploited vulnerabilities.

• Train users to recognize and report phishing attempts.

• Enable and enforce multifactor authentication.

Note: this joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint CSA to disseminate known Zeppelin ransomware IOCs and TTPs associated with ransomware variants identified through FBI investigations as recently as 21 June 2022.

The FBI and CISA encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of ransomware incidents.

Download the PDF version of this report: pdf, 999 kb

Download the YARA signature for Zeppelin: YARA Signature, .yar 125 kb

Download the IOCs: .stix 113 kb

Technical Details

Note: this advisory uses the MITRE ATT&CK® for Enterprise framework, version 11. See MITRE ATT&CK for Enterprise for all referenced tactics and techniques.

Zeppelin ransomware is a derivative of the Delphi-based Vega malware family and functions as a Ransomware as a Service (RaaS). From 2019 through at least June 2022, actors have used this malware to target a wide range of businesses and critical infrastructure organizations, including defense contractors, educational institutions, manufacturers, technology companies, and especially organizations in the healthcare and medical industries. Zeppelin actors have been known to request ransom payments in Bitcoin, with initial amounts ranging from several thousand dollars to over a million dollars.

Zeppelin actors gain access to victim networks via RDP exploitation [T1133], exploiting SonicWall firewall vulnerabilities [T1190], and phishing campaigns [T1566]. Prior to deploying Zeppelin ransomware, actors spend one to two weeks mapping or enumerating the victim network to identify data enclaves, including cloud storage and network backups [TA0007]. Zeppelin actors can deploy Zeppelin ransomware as a .dll or .exe file or contained within a PowerShell loader. [1]

Prior to encryption, Zeppelin actors exfiltrate [TA0010] sensitive company data files to sell or publish in the event the victim refuses to pay the ransom. Once the ransomware is executed, a randomized nine-digit hexadecimal number is appended to each encrypted file as a file extension, e.g., file.txt.txt.C59-E0C-929 [T1486]. A note file with a ransom note is left on compromised systems, frequently on the desktop (see figure 1 below).

Figure 1: Sample Ransom Note

The FBI has observed instances where Zeppelin actors executed their malware multiple times within a victim’s network, resulting in the creation of different IDs or file extensions, for each instance of an attack; this results in the victim needing several unique decryption keys.

Indicators of Compromise (IOC)

See table 1 below for IOCs as of June 2022 obtained from FBI incident response investigations.

MD5

|

SHA1

|

SHA256

—|—|—

981526650af8d6f8f20177a26abb513a

|

4fee2cb5c98abbe556e9c7ccfebe9df4f8cde53f

|

001938ed01bfde6b100927ff8199c65d1bff30381b80b846f2e3fe5a0d2df21d

c25d45e9bbfea29cb6d9ee0d9bf2864d

|

eaeff8d315cca71e997063a2baec5cc73fad9453

|

a42185d506e08160cb96c81801fbe173fb071f4a2f284830580541e057f4423b

183b6b0c90c1e0276a2015752344a4cf

|

1cb5e8132302b420af9b1e5f333c507d8b2a2441

|

aa7e2d63fc991990958dfb795a0aed254149f185f403231eaebe35147f4b5ebe

9349e1cc3de7c7f6893a21bd6c3c4a6b

|

db398e38ee6221df7e4aa49d8f96799cca4d87e1

|

a2a9385cbbcfacc2d541f5bd92c38b0376b15002901b2fd1cc62859e161a8037

c8f75487d0d496a3746e6c81a5ecc6dc

|

4b91a91a98a2f0128c80f8ceeef0f5d293adf0cd

|

54d567812eca7fc5f2ff566e7fb8a93618b6d2357ce71776238e0b94d55172b1

477eedb422041385e59a4fff72cb97c1

|

9892cc90e6712d3548e45f34f14f362bccedf0be

|

fb59f163a2372d09cd0fc75341d3972fdd3087d2d507961303656b1d791b17c6

5841ef35aaff08bb03d25e5afe3856a2

|

ffd228b0d7afe7cab4e9734f7093e7ba01c5a06e

|

1e3c5a0aa079f8dfcc49cdca82891ab78d016a919d9810120b79c5deb332f388

d6c4b253ab1d169cf312fec12cc9a28f

|

0f47c279fea1423c7a0e7bc967d9ff3fae7a0de8

|

347f14497df4df73bc414f4e852c5490b12db991a4b3811712bac7476a3f1bc9

fba7180ad49d6a7f3c60c890e2784704

|

f561f9e3c949fe87f12dbfa166ffb2eb85712419

|

7d8c4c742689c097ac861fcbf7734709fd7dcab1f7ef2ceffb4b0b7dec109f55

bc6c991941d9afbd522fa0a2a248a97a

|

a243ce234fc8294e2e2e526418b4eaadc2d6c84f

|

37c320983ae4c1fd0897736a53e5b0481edb1d1d91b366f047aa024b0fc0a86e

f3490951ae51922cb360a3d76a670159

|

e2cb60be111716e32db7ca2365ad6e73c30f0e21

|

894b03ed203cfa712a28ec472efec0ca9a55d6058115970fe7d1697a3ddb0072

e4f1f05c2e6c3fc2f3336a8c8799ffb4

|

dbd9fcf2b05e703d34181c46f4c22392b9fcc1da

|

307877881957a297e41d75c84e9a965f1cd07ac9d026314dcaff55c4da23d03e

aa2048271f0aef3383480ce4a7c93b52

|

512b16ea74027fa4d0055831de5e51278812c8de

|

bafd3434f3ba5bb9685e239762281d4c7504de7e0cfd9d6394e4a85b4882ff5d

f66b738e1bfe1f8aab510abed850c424

|

571f50fee0acad1da39fe06c75116461800cc719

|

faa79c796c27b11c4f007023e50509662eac4bca99a71b26a9122c260abfb3c6

bb30f050546f5d6e61fafc59eaf097c3

|

ee44179f64918f72a8d2e88a5074d89efab3d81b

|

e48cf17caffc40815efb907e522475722f059990afc19ac516592231a783e878

78621f1e196497d440afb57f4609fcf9

|

eed7c3bb3fc5181b88abeed2204997f350324022

|

4a4be110d587421ad50d2b1a38b108fa05f314631066a2e96a1c85cc05814080

f4e0ee0200de397691748a2cdcd7e34a

|

bd3f6b878284a63c72e8354e877e3f48d6fca53c

|

9ef90ec912543cc24e18e73299296f14cb2c931a5d633d4c097efa372ae59846

cf5a358a22326f09fd55983bb812b7d8

|

1addcffae4fd4211ea24202783c2ffad6771aa34

|

dd89d939c941a53d6188232288a3bd73ba9baf0b4ca6bf6ccca697d9ee42533f

7afe492a38ca6f27e24028aab68406b5

|

5870a3adbce9737319f3c9461586d5f2afbc7adb

|

79d6e498e7789aaccd8caa610e8c15836267c6a668c322111708cf80bc38286c

1da1c0115caca5ebf064380eb7490041

|

5edb8b651c7013ebaba2eb81c87df76a1e0724d6

|

b22b3625bcce7b010c0ee621434878c5f8d7691c2a101ae248dd221a70668ac0

8c3c663ffcf363d087f4e114a79945ca

|

905726d178962dd1d7fe87504d051aca440740b8

|

961fbc7641f04f9fed8391c387f01d64435dda6af1164be58c4cb808b08cc910

17c5cae3bce5832dd42986fe612517d9

|

6f70e73c53d7622d8c4808ae7849133df1343484

|

d618c1ccd24d29e911cd3e899a4df2625155297e80f4c5c1354bc2e79f70768c

bfe7f54f1f0640936dd7a3384608b1f6

|

9436ccee41c01ca3cb4db55c10884615aba76d19

|

8170612574f914eec9e66902767b834432a75b1d6ae510f77546af2a291a48a2

f28af04ef0370addfebfdd31f1ec25ed

|

cfcfa995c15d9f33de21d0dd88d3b95d0f91d6bc

|

5326f52bd9a7a52759fe2fde3407dc28e8c2caa33abf1c09c47b192a1c004c12

f3bcad5358f89df1eb0294ef53f54437

|

eb036759beb28f86ee981bdca4fad24152b82d8c

|

6bafc7e2c7edc2167db187f50106e57b49d4a0e1b9269f1d8a40f824f2ccb42b

b1f6370582fbaf5c51e826fecef53cd7

|

4b2d0127699f708a8116bff8f25c9d6140033197

|

f7af51f1b2b98b482885b702508bd65d310108a506e6d8cef3986e69f972c67d

de785ed922d4e737dc0fa0bb30a4de8b

|

4d280105e724db851f03de8fc76409ef4057ff2c

|

bc214c74bdf6f6781f0de994750ba3c50c0e10d9db3483183bd47f5cef154509

7a296f7c1ac4aeee18d4c23476735be7

|

c13542310f7a4e50a78247fc7334096ca09c5d7f

|

ed1548744db512a5502474116828f75737aec8bb11133d5e4ad44be16aa3666b

37f18b38e1af6533d93bbb3f2ddb86dc

|

d3929331d9bc278dea5607aec1574012a08de861

|

cf9b6dda84cbf2dbfc6edd7a740f50bddc128842565c590d8126e5d93c024ff2

291de974e5cbe5e3d47e3d17487e027f

|

def93f18aaf146fe8f3c4f9a257364f181197608

|

21807d9fcaa91a0945e80d92778760e7856268883d36139a1ad29ab91f9d983d

99d59c862a082b207a868e409ce2d97c

|

908a9026d61717b5fa29959478a9bd939da9206f

|

0d22d3d637930e7c26a0f16513ec438243a8a01ea9c9d856acbcda61fcb7b499

d27125d534e398f1873b7f4835a79f09

|

1862f063c30cd02cfea6070d3dba41ac5eee2a35

|

6fbfc8319ed7996761b613c18c8cb6b92a1eaed1555dae6c6b8e2594ac5fa2b9

4534f2afe5f7df1d998f37ad4e35afeb

|

e2cc94e471509f9fa58620b8bb56d77f2cfe74b0

|

e8596675fef4ad8378e4220c22f4358fdb4a20531b59d7df5382c421867520a9

7ab0676262c681b8ec15bdada17d7476

|

2f1803d444891abb604864d476a8feac0d614f77

|

353e59e96cbf6ea6c16d06da5579d3815aaaeeefacabd7b35ba31f7b17207c5b

d7d3d23a5e796be844af443bda5cd67e

|

a9771c591f6ccc2f3419d571c64ab93228785771

|

85f9bf4d07bc2ac1891e367f077dd513d6ca07705bffd1b648d32a7b2dc396f5

0a1cd4efda7543cec406a6822418daf6

|

af4f8d889d6a2049e7a379ea197f8cd361feb074

|

614cb70659ef5bb2f641f09785adc4ab5873e0564a5303252d3c141a899253b2

23eda650479fc4908d0ddff713508025

|

b1e6527c10f68586f7f1a279ed439d46c3f12a06

|

fb3e0f1e6f53ffe680d66d2143f06eb6363897d374dc5dc63eb2f28188b8ad83

6607d8c1a28d7538e2a6565cf40d1260

|

f618879c011cde344066072949f025827feea663

|

594df9c402abfdc3c838d871c3395ac047f256b2ac2fd6ff66b371252978348d

caa7a669da39ffd8a3a4f3419018b363

|

44538b7f8f065e3cef0049089a8522a76a7fccc6

|

2dffe3ba5c70af51ddf0ff5a322eba0746f3bf3ae0751beb3dc0059ed3faaf3d

48b844494a746ca96c7b96d6bd90f45f

|

7bf83b98f798f3a8f4ce85b6d29554a435e516e3

|

45fba1ef399f41227ae4d14228253237b5eb464f56cab92c91a6a964dc790622

9c13ab7b79aec8dc02869999773cd4b2

|

4b4d865132329e0dd1d129e85fc4fa9ad0c1d206

|

774ef04333c3fb2a6a4407654e28c2900c62bd202ad6e5909336eb9bc180d279

450e5bf4b42691924d09267ac1a570cb

|

665a563157f4aa0033a15c88f55ac4fa28397b49

|

677035259ba8342f1a624fd09168c42017bdca9ebc0b39bf6c37852899331460

51104215a618a5f56ad9c884d6832f79

|

801580a46f9759ceeeebbce419d879e2ed6943fe

|

26ec12b63c0e4e60d839aea592c4b5dcff853589b53626e1dbf8c656f4ee6c64

73627cbe2ba139e2ec26889a4e8d6284

|

1116dc35993fce8118e1e5421000a70b6777433f

|

37efe10b04090995e2f3d9f932c3653b27a65fc76811fa583934a725d41a6b08

935f54b6609c5339001579e96dc34244

|

a809327d39fab61bfcfac0c97b1d4b3bfb9a2cfe

|

a5847867730e7849117c31cdae8bb0a25004635d49f366fbfaebce034d865d7d

ba681db97f283c2e784d9bb4969b1f5a

|

5d28acf52f399793e82ec7e79da47d372d9175d7

|

e61edbddf9aed8a52e9be1165a0440f1b6e9943ae634148df0d0517a0cf2db13

c1ab7b68262b5ab31c45327e7138fd25

|

b8c74327831e460d2b2a8eb7e68ee68938779d8d

|

746f0c02c832b079aec221c04d2a4eb790287f6d10d39b95595a7df4086f457f

f818938b987236cdd41195796b4c1fb5

|

bfed40f050175935277c802cbbbce132f44c06ec

|

b191a004b6d8a706aba82a2d1052bcb7bed0c286a0a6e4e0c4723f073af52e7c

0a1cd4efda7543cec406a6822418daf6

|

af4f8d889d6a2049e7a379ea197f8cd361feb074

|

614cb70659ef5bb2f641f09785adc4ab5873e0564a5303252d3c141a899253b2

d7d3d23a5e796be844af443bda5cd67e

|

a9771c591f6ccc2f3419d571c64ab93228785771

|

85f9bf4d07bc2ac1891e367f077dd513d6ca07705bffd1b648d32a7b2dc396f5

7ab0676262c681b8ec15bdada17d7476

|

2f1803d444891abb604864d476a8feac0d614f77

|

353e59e96cbf6ea6c16d06da5579d3815aaaeeefacabd7b35ba31f7b17207c5b

4534f2afe5f7df1d998f37ad4e35afeb

|

e2cc94e471509f9fa58620b8bb56d77f2cfe74b0

|

e8596675fef4ad8378e4220c22f4358fdb4a20531b59d7df5382c421867520a9

d27125d534e398f1873b7f4835a79f09

|

1862f063c30cd02cfea6070d3dba41ac5eee2a35

|

6fbfc8319ed7996761b613c18c8cb6b92a1eaed1555dae6c6b8e2594ac5fa2b9

99d59c862a082b207a868e409ce2d97c

|

908a9026d61717b5fa29959478a9bd939da9206f

|

0d22d3d637930e7c26a0f16513ec438243a8a01ea9c9d856acbcda61fcb7b499

MITRE ATT&CK TECHNIQUES

Zeppelin actors use the ATT&CK techniques listed in Table 2.

Table 2: Zeppelin Actors Att&ck Techniques for Enterprise

Initial Access

---

Technique Title

|

ID

|

Use

Exploit External Remote Services

|

T1133

|

Zeppelin actors exploit RDP to gain access to victim networks.

Exploit

Public-Facing Application

|

T1190

|

Zeppelin actors exploit vulnerabilities in internet-facing systems to gain access to systems

Phishing

|

T1566

|

Zeppelin actors have used phishing and spear phishing to gain access to victims’ networks.

Execution

Technique Title

|

ID

|

Use

Malicious Link

|

T1204.001

|

Zeppelin actors trick users to click a malicious link to execute malicious macros.

Malicious File Attachment

|

T1204.002

|

Zeppelin actors trick users to click a malicious attachment disguised as advertisements to execute malicious macros.

Persistence

Technique Title

|

ID

|

Use

Modify System Process

|

T1543.003

|

Zeppelin actors encrypt Windows Operating functions to preserve compromised system functions.

Impact

Technique Title

|

ID

|

Use

Data Encrypted for Impact

|

T1486

|

Zeppelin actors have encrypted data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources.

DETECTION

Download the YARA signature for Zeppelin: YARA Signature, .yar 125 kb

Mitigations

The FBI and CISA recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques and to reduce the risk of compromise by Zeppelin ransomware:

• Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, the cloud).
• Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts)**to comply **with National Institute for Standards and Technology (NIST) standards for developing and managing password policies.
  • Use longer passwords consisting of at least 8 characters and no more than 64 characters in length;
  • Store passwords in hashed format using industry-recognized password managers;
  • Add password user “salts” to shared login credentials;
  • Avoid reusing passwords;
  • Implement multiple failed login attempt account lockouts;
  • Disable password “hints”;
  • Refrain from requiring password changes more frequently than once per year. Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher.
  • Require administrator credentials to install software.
• Require multifactor authentication for all services to the extent possible, particularly for webmail, virtual private networks, and accounts that access critical systems.
• **Keep all operating systems, software, and firmware up to date.**Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats. Prioritize patching SonicWall firewall vulnerabilities and known exploited vulnerabilities in internet-facing systems. Note: SonicWall maintains a vulnerability list that includes Advisory ID, CVE, and mitigation. Their list can be found at psirt.global.sonicwall.com/vuln-list.
• Segment networks to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks and by restricting adversary lateral movement.
• **Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool.**To aid in detecting the ransomware, implement a tool that logs and reports all network traffic, including lateral movement activity on a network. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
• Install, regularly update, and enable real time detection for antivirus software on all hosts.
• Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts.
• Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege.
• Disable unused ports. *Consider adding an email banner to emails received from outside your organization.
• Disable hyperlinks in received emails.
• Implement time-based access for accounts set at the admin level and higher. For example, the Just-in-Time (JIT) access method provisions privileged access when needed and can support enforcement of the principle of least privilege (as well as the Zero Trust model). This is a process where a network-wide policy is set in place to automatically disable admin accounts at the Active Directory level when the account is not in direct need. Individual users may submit their requests through an automated process that grants them access to a specified system for a set timeframe when they need to support the completion of a certain task.
• Disable command-line and scripting activities and permissions. Privilege escalation and lateral movement often depend on software utilities running from the command line. If threat actors are not able to run these tools, they will have difficulty escalating privileges and/or moving laterally.
• Maintain offline backups of data, and regularly maintain backup and restoration. By instituting this practice, the organization ensures they will not be severely interrupted, and/or only have irretrievable data.
• Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure.

RESOURCES

• Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts.
• Resource to mitigate a ransomware attack: CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide.
• No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment.

REPORTING

The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with Zeppelin actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. The FBI and CISA do not encourage paying ransom as payment does not guarantee victim files will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Regardless of whether you or your organization have decided to pay the ransom, the FBI and CISA urge you to promptly report ransomware incidents to a local FBI Field Office, CISA at us-cert.cisa.gov/report, or the U.S. Secret Service (USSS) at a USSS Field Office.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. CISA and the FBI do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by CISA or the FBI.

References

[1] What is Zeppelin Ransomware? Steps to Prepare, Respond, and Prevent Infection (coresecurity.com)

Revisions

August 11, 2022: Initial Version