#StopRansomware: Cuba 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 phishing-resistant 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 FBI and the Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint CSA to disseminate known Cuba ransomware IOCs and TTPs associated with Cuba ransomware actors identified through FBI investigations, third-party reporting, and open-source reporting. This advisory updates the December 2021 FBI Flash: Indicators of Compromise Associated with Cuba Ransomware.

Note: While this ransomware is known by industry as “Cuba ransomware,” there is no indication Cuba ransomware actors have any connection or affiliation with the Republic of Cuba.

Since the release of the December 2021 FBI Flash, the number of U.S. entities compromised by Cuba ransomware has doubled, with ransoms demanded and paid on the increase.

This year, Cuba ransomware actors have added to their TTPs, and third-party and open-source reports have identified a possible link between Cuba ransomware actors, RomCom Remote Access Trojan (RAT) actors, and Industrial Spy ransomware actors.

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

Download the PDF version of this report: pdf, 649 kb.

For a downloadable copy of IOCs, see:

• AA22-335A.stix (STIX 148 kb).
• (Updated December 12, 2022) AA22-335A-2.stix (STIX, 67 kb).(End of Update.)

Technical Details

Overview

Since the December 2021 release of FBI Flash: Indicators of Compromise Associated with Cuba Ransomware, FBI has observed Cuba ransomware actors continuing to target U.S. entities in the following five critical infrastructure sectors: Financial Services, Government Facilities, Healthcare and Public Health, Critical Manufacturing, and Information Technology. As of August 2022, FBI has identified that Cuba ransomware actors have:

• Compromised 101 entities, 65 in the United States and 36 outside the United States.
• Demanded 145 million U.S. Dollars (USD) and received 60 million USD in ransom payments.

Cuba Ransomware Actors’ Tactics, Techniques, and Procedures

As previously reported by FBI, Cuba ransomware actors have leveraged the following techniques to gain initial access into dozens of entities in multiple critical infrastructure sectors:

• Known vulnerabilities in commercial software [T1190]
• Phishing campaigns [T1566]
• Compromised credentials [T1078]
• Legitimate remote desktop protocol (RDP) tools [T1563.002]

After gaining initial access, the actors distributed Cuba ransomware on compromised systems through Hancitor—a loader known for dropping or executing stealers, such as Remote Access Trojans (RATs) and other types of ransomware, onto victims’ networks.

Since spring 2022, Cuba ransomware actors have modified their TTPs and tools to interact with compromised networks and extort payments from victims.[1],[2]

Cuba ransomware actors have exploited known vulnerabilities and weaknesses and have used tools to elevate privileges on compromised systems. According to Palo Alto Networks Unit 42,[2] Cuba ransomware actors have:

• Exploited CVE-2022-24521 in the Windows Common Log File System (CLFS) driver to steal system tokens and elevate privileges.
• Used a PowerShell script to identify and target service accounts for their associated Active Directory Kerberos ticket. The actors then collected and cracked the Kerberos tickets offline via Kerberoasting [T1558.003].
• Used a tool, called KerberCache, to extract cached Kerberos tickets from a host’s Local Security Authority Server Service (LSASS) memory [T1003.001].
• Used a tool to exploit CVE-2020-1472 (also known as “ZeroLogon”) to gain Domain Administrative privileges [T1068]. This tool and its intrusion attempts have been reportedly related to Hancitor and Qbot.

According to Palo Alto Networks Unit 42, Cuba ransomware actors use tools to evade detection while moving laterally through compromised environments before executing Cuba ransomware. Specifically, the actors, “leveraged a dropper that writes a kernel driver to the file system called ApcHelper.sys. This targets and terminates security products. The dropper was not signed; however, the kernel driver was signed using the certificate found in the LAPSUS NVIDIA leak." [T1562.001].[2]

In addition to deploying ransomware, the actors have used “double extortion” techniques, in which they exfiltrate victim data, and (1) demand a ransom payment to decrypt it and, (2) threaten to publicly release it if a ransom payment is not made.[2]

Cuba Ransomware Link to RomCom and Industrial Spy Marketplace

Since spring 2022, third-party and open-source reports have identified an apparent link between Cuba ransomware actors, RomCom RAT actors, and Industrial Spy ransomware actors:

• According to Palo Alto Networks Unit 42, Cuba ransomware actors began using RomCom malware, a custom RAT, for command and control (C2).[2]
• Cuba ransomware actors may also be leveraging Industrial Spy ransomware. According to third-party reporting, suspected Cuba ransomware actors compromised a foreign healthcare company. The threat actors deployed Industrial Spy ransomware, which shares distinct similarities in configuration to Cuba ransomware. Before deploying the ransomware, the actors moved laterally using Impacket and deployed the RomCom RAT and Meterpreter Reverse Shell HTTP/HTTPS proxy via a C2 server [T1090].
• Cuba ransomware actors initially used their leak site to sell stolen data; however, around May 2022, the actors began selling their data on Industrial Spy’s online market for selling stolen data.[2]

RomCom actors have targeted foreign military organizations, IT companies, food brokers and manufacturers.[3][4] The actors copied legitimate HTML code from public-facing webpages, modified the code, and then incorporated it in spoofed domains [T1584.001], which allowed the RomCom actors to:

• Host counterfeit Trojanized applications for
  • SolarWinds Network Performance Monitor (NPM),
  • KeePass password manager,
  • PDF Reader Pro, (by PDF Technologies, Inc., not an Adobe Acrobat or Reader product), and
  • Advanced IP Scanner software;
• Deploy the RomCom RAT as the final stage.

INDICATORS OF COMPROMISE

See tables 1 through 5 for Cuba ransomware IOCs that FBI obtained during threat response investigations as of late August 2022. In addition to these tables, see the publications in the References section below for aid in detecting possible exploitation or compromise.

Note: For IOCs as of early November 2021, see FBI Flash: Indicators of Compromise Associated with Cuba Ransomware.

Table 1: Cuba Ransomware Associated Files and Hashes, as of Late August 2022

File Name

|

File Path

|

File Hash

—|—|—

netping.dll

|

c:\windows\temp

|

SHA256: f1103e627311e73d5f29e877243e7ca203292f9419303c661aec57745eb4f26c

shar.bat

|

|

MD5: 4c32ef0836a0af7025e97c6253054bca

SHA256: a7c207b9b83648f69d6387780b1168e2f1eabd23ae6e162dd700ae8112f8b96c

Psexesvc.exe

|

|

SHA256: 141b2190f51397dbd0dfde0e3904b264c91b6f81febc823ff0c33da980b69944

1.bat

|

|

216155s.dll

|

|

23246s.bat

|

|

SHA256: 02a733920c7e69469164316e3e96850d55fca9f5f9d19a241fad906466ec8ae8

23246s.dll

|

|

SHA256: 0cf6399db55d40bc790a399c6bbded375f5a278dc57a143e4b21ea3f402f551f

23246st.dll

|

|

SHA256: f5db51115fa0c910262828d0943171d640b4748e51c9a140d06ea81ae6ea1710

259238e.exe

|

|

31-100.bat

|

|

3184.bat

|

|

3184.dll

|

|

45.dll

|

|

SHA256:

857f28b8fe31cf5db6d45d909547b151a66532951f26cda5f3320d2d4461b583

4ca736d.exe

|

|

62e2e37.exe

|

|

64.235.39.82

|

|

64s.dll

|

|

7z.sfx

|

|

7zCon.sfx

|

|

7-zip.chm

|

|

82.ps1

|

|

9479.bat

|

|

SHA256: 08eb4366fc0722696edb03981f00778701266a2e57c40cd2e9d765bf8b0a34d0

9479p.bat

|

|

SHA256: f8144fa96c036a8204c7bc285e295f9cd2d1deb0379e39ee8a8414531104dc4a

9479p.ps1

|

|

SHA256: 88d13669a994d2e04ec0a9940f07ab8aab8563eb845a9c13f2b0fec497df5b17

a.exe

|

|

MD5: 03c835b684b21ded9a4ab285e4f686a3

SHA1: eaced2fcfdcbf3dca4dd77333aaab055345f3ab4

SHA256: 0f385cc69a93abeaf84994e7887cb173e889d309a515b55b2205805bdfe468a3

SHA256: 0d5e3483299242bf504bd3780487f66f2ec4f48a7b38baa6c6bc8ba16e4fb605

SHA256: 7e00bfb622072f53733074795ab581cf6d1a8b4fc269a50919dda6350209913c

SHA256: af4523186fe4a5e2833bbbe14939d8c3bd352a47a2f77592d8adcb569621ce02

a220.bat

|

|

a220.dll

|

|

SHA256: 8a3d71c668574ad6e7406d3227ba5adc5a230dd3057edddc4d0ec5f8134d76c3

a82.exe

|

|

SHA256: 4306c5d152cdd86f3506f91633ef3ae7d8cf0dd25f3e37bec43423c4742f4c42

a91.exe

|

|

SHA256: 3d4502066a338e19df58aa4936c37427feecce9ab8d43abff4a7367643ae39ce

a99.exe

|

|

SHA256: f538b035c3de87f9f8294bec272c1182f90832a4e86db1e47cbb1ab26c9f3a0b

aa.exe

|

|

aa2.exe

|

|

aaa.stage.16549040.dns.alleivice.com

|

|

add2.exe

|

|

advapi32.dll

|

|

agent.13.ps1

|

|

agent.bat

|

|

SHA256: fd87ca28899823b37b2c239fbbd236c555bcab7768d67203f86d37ede19dd975

agent.dll

|

|

agent13.bat

|

|

agent13.ps1

|

|

SHA256: 1817cc163482eb21308adbd43fb6be57fcb5ff11fd74b344469190bb48d8163b

agent64.bin

|

|

SHA256: bff4dd37febd5465e0091d9ea68006be475c0191bd8c7a79a44fbf4b99544ef1

agsyst121.bat

|

|

agsyst121.dll

|

|

all.bat

|

|

SHA256: ecefd9bb8b3783a81ab934b44eb3d84df5e58f0289f089ef6760264352cf878a

all.dll

|

|

SHA256: db3b1f224aec1a7c58946d819d729d0903751d1867113aae5cca87e38c653cf4

anet.exe

|

|

SHA1: 241ce8af441db2d61f3eb7852f434642739a6cc3

SHA256: 74fbf3cc44dd070bd5cb87ca2eed03e1bbeec4fec644a25621052f0a73abbe84

SHA256: b160bd46b6efc6d79bfb76cf3eeacca2300050248969decba139e9e1cbeebf53

SHA256: f869e8fbd8aa1f037ad862cf6e8bbbf797ff49556fb100f2197be4ee196a89ae

App.exe

|

|

appnetwork.exe

|

|

AppVClient.man

|

|

aswSP_arPot2

|

|

aus.exe

|

|

SHA256: 0c2ffed470e954d2bf22807ba52c1ffd1ecce15779c0afdf15c292e3444cf674

SHA256: 310afba59ab8e1bda3ef750a64bf39133e15c89e8c7cf4ac65ee463b26b136ba

av.bat

|

|

SHA256: b5d202456ac2ce7d1285b9c0e2e5b7ddc03da1cbca51b5da98d9ad72e7f773b8

c2.ps1

|

|

c2.ps1

|

|

cdzehhlzcwvzcmcr.aspx

|

|

check.exe

|

|

checkk.exe

|

|

checkk.txt

|

|

SHA256: 1f842f84750048bb44843c277edeaa8469697e97c4dbf8dc571ec552266bec9f

client32.exe

|

|

comctl32 .dll

|

|

comp2.ps1

|

|

comps2.ps1

|

|

cqyrrxzhumiklndm.aspx

|

|

defendercontrol.exe

|

|

ff.exe

|

|

SHA256: 1b943afac4f476d523310b8e3afe7bca761b8cbaa9ea2b9f01237ca4652fc834

File __agsyst121.dll

|

|

File __aswArPot.sys

|

|

File __s9239.dll

|

|

File_agsyst121.dll

|

|

File_aswArPot.sys

|

|

File_s9239.dll

|

|

ga.exe

|

|

gdi32 .dll

|

|

geumspbgvvytqrih.aspx

|

|

IObit UNLOCKER.exe

|

|

kavsa32.exe

|

|

MD5: 236f5de8620a6255f9003d054f08574b

SHA1: 9b546bd99272cf4689194d698c830a2510194722

kavsyst32.exe

|

|

kernel32.dll

|

|

komar.bat

|

|

SHA256: B9AFE016DBDBA389000B01CE7645E7EEA1B0A50827CDED1CBAA48FBC715197BB

komar.dll

|

|

komar121.bat

|

|

komar121.dll

|

|

komar2.ps1

|

|

SHA256: 61971d3cbf88d6658e5209de443e212100afc8f033057d9a4e79000f6f0f7cc4

komar64.dll

|

|

SHA256: 8E64BACAF40110547B334EADCB0792BDC891D7AE298FBFFF1367125797B6036B

mfcappk32.exe

|

|

newpass.ps1

|

|

SHA256: c646199a9799b6158de419b1b7e36b46c7b7413d6c35bfffaeaa8700b2dcc427

npalll.exe

|

|

SHA256: bd270853db17f94c2b8e4bd9fa089756a147ed45cbc44d6c2b0c78f361978906

ole32.dll

|

|

oleaut32.dll

|

|

open.bat

|

|

SHA256: 2EB3EF8A7A2C498E87F3820510752043B20CBE35B0CBD9AF3F69E8B8FE482676

open.exe

|

|

pass.ps1

|

|

SHA256: 0afed8d1b7c36008de188c20d7f0e2283251a174261547aab7fb56e31d767666

pdfdecrypt.exe

|

|

powerview.ps1

|

|

prt3389.bat

|

|

SHA256: e0d89c88378dcb1b6c9ce2d2820f8d773613402998b8dcdb024858010dec72ed

ra.ps1

|

|

SHA256: 571f8db67d463ae80098edc7a1a0cad59153ce6592e42d370a45df46f18a4ad8

rg1.exe

|

|

Rg2.exe

|

|

rundll32

|

|

s64174.bat

|

|

SHA256: 10a5612044599128981cb41d71d7390c15e7a2a0c2848ad751c3da1cbec510a2

SHA256: 1807549af1c8fdc5b04c564f4026e41790c554f339514d326f8b55cb7b9b4f79

s64174.dll

|

|

s9239.bat

|

|

s9239.dll

|

|

shell32.dll

|

|

stel.exe

|

|

syskav64.exe

|

|

sysra64,exe

|

|

systav332.bat

|

|

SHA256: 01242b35b6def71e42cc985e97d618e2fabd616b16d23f7081d575364d09ca74

TC-9.22a.2019.3.exe

|

|

TeamViewer.exe

|

|

testDLL.dll

|

|

tug4rigd.dll

|

|

SHA256: 952b34f6370294c5a0bb122febfaa80612fef1f32eddd48a3d0556c4286b7474

UpdateNotificationPipeline.002.etl

|

|

user32.dll

|

|

v1.bat

|

|

v2.bat

|

|

v3.bat

|

|

veeamp.exe

|

|

SHA256: 9aa1f37517458d635eae4f9b43cb4770880ea0ee171e7e4ad155bbdee0cbe732

version.dll

|

|

vlhqbgvudfnirmzx.aspx

|

|

wininet.dll

|

|

wlog.exe

|

|

wpeqawzp.sys

|

|

y3lcx345.dll

|

|

zero.exe

|

|

SHA256: 3a8b7c1fe9bd9451c0a51e4122605efc98e7e4e13ed117139a13e4749e211ed0

|

|

|

|

Table 2: Cuba Ransomware Associated Email Addresses, as of Late August 2022

Email Provider

|

Email Addresses

—|—

Cuba-supp[.]com

|

admin@cuba-supp[.]com

Encryption-support[.]com

|

admin@encryption-support[.]com

Mail.supports24[.]net

|

[email protected][.]net

Table 3: Cuba Ransomware Associated Jabber Address, as of Late August 2022

cuba_support@exploit[.]im

---

_Table 4: IP Addresses Associated with Cuba Ransomware, as of Late August 2022

Note: Some of these observed IP addresses are more than a year old. FBI and CISA recommend vetting or investigating these IP addresses prior to taking forward-looking action such as blocking. _

193.23.244[.]244

|

144.172.83[.]13

|

216.45.55[.]30

—|—|—

94.103.9[.]79

|

149.255.35[.]131

|

217.79.43[.]148

192.137.101[.]46

|

154.35.175[.]225

|

222.252.53[.]33

92.222.172[.]39

|

159.203.70[.]39

|

23.227.198[.]246

92.222.172[.]172

|

171.25.193[.]9

|

31.184.192[.]44

10.13.102[.]1

|

185.153.199[.]169

|

37.120.247[.]39

10.13.102[.]58

|

192.137.100[.]96

|

37.44.253[.]21

10.133.78[.]41

|

192.137.100[.]98

|

38.108.119[.]121

10.14.100[.]20

|

192.137.101[.]205

|

45.164.21[.]13

103.114.163[.]197

|

193.34.167[.]17

|

45.32.229[.]66

103.27.203[.]197

|

194.109.206[.]212

|

45.86.162[.]34

104.217.8[.]100

|

195.54.160[.]149

|

45.91.83[.]176

107.189.10[.]143

|

199.58.81[.]140

|

64.52.169[.]174

108.170.31[.]115

|

204.13.164[.]118

|

64.235.39[.]82

128.31.0[.]34

|

209.76.253[.]84

|

79.141.169[.]220

128.31.0[.]39

|

212.192.241[.]230

|

84.17.52[.]135

131.188.40[.]189

|

213.32.39[.]43

|

86.59.21[.]38

141.98.87[.]124

|

216.45.55[.]3

|

Table 5: Cuba Bitcoin Wallets Receiving Payments, as of Late August 2022

bc1q4vr25xkth35qslenqwd7aw020w85qrvlrhv7hc

---

bc1q5uc0fdnz0ve5pg4nl4upa9ly586t6wmnghfe7x

bc1q6rsj3cn37dngypu5kad9gdw5ykhctpwhjvun3z

bc1q6zkemtyyrre2mkk23g93zyq98ygrygvx7z2q0t

bc1q9cj0n9k2m282x0nzj6lhqjvhkkd4h95sewek83

bc1qaselp9nhejc3safcq3vn5wautx6w33x0llk7dl

bc1qc48q628t93xwzljtvurpqhcvahvesadpwqtsza

bc1qgsuf5m9tgxuv4ylxcmx8eeqn3wmlmu7f49zkus

bc1qhpepeeh7hlz5jvrp50uhkz59lhakcfvme0w9qh

bc1qjep0vx2lap93455p7h29unruvr05cs242mrcah

bc1qr9l0gcl0nvmngap6ueyy5gqdwvm34kdmtevjyx

bc1qs3lv77udkap2enxv928x59yuact5df4t95rsqr

bc1qyd05q2m5qt3nwpd3gcqkyer0gspqx5p6evcf7h

bc1qzz7xweq8ee2j35tq6r5m687kctq9huskt50edv

bc1qvpk8ksl3my6kjezjss9p28cqj4dmpmmjx5yl3y

bc1qhtwfcysclc7pck2y3vmjtpzkaezhcm6perc99x

bc1qft3s53ur5uq5ru6sl3zyr247dpr55mnggwucd3

bc1qp7h9fszlqxjwyfhv0upparnsgx56x7v7wfx4x7

bc1q4vr25xkth35qslenqwd7aw020w85qrvlrhv7hc

bc1q5uc0fdnz0ve5pg4nl4upa9ly586t6wmnghfe7x

bc1q6rsj3cn37dngypu5kad9gdw5ykhctpwhjvun3z

bc1q6zkemtyyrre2mkk23g93zyq98ygrygvx7z2q0t

bc1q9cj0n9k2m282x0nzj6lhqjvhkkd4h95sewek83

bc1qaselp9nhejc3safcq3vn5wautx6w33x0llk7dl

bc1qc48q628t93xwzljtvurpqhcvahvesadpwqtsza

bc1qgsuf5m9tgxuv4ylxcmx8eeqn3wmlmu7f49zkus

bc1qhpepeeh7hlz5jvrp50uhkz59lhakcfvme0w9qh

bc1qjep0vx2lap93455p7h29unruvr05cs242mrcah

bc1qr9l0gcl0nvmngap6ueyy5gqdwvm34kdmtevjyx

bc1qs3lv77udkap2enxv928x59yuact5df4t95rsqr

bc1qyd05q2m5qt3nwpd3gcqkyer0gspqx5p6evcf7h

bc1qzz7xweq8ee2j35tq6r5m687kctq9huskt50edv

See figure 1 for an example of a Cuba ransomware note.

Figure 1: Sample Cuba Ransom Note 2, as of late August 2022

Greetings! Unfortunately we have to report that your company were

compromised. All your files were

encrypted and you can’t restore them without our private key. Trying

to restore it without our help may

cause complete loss of your data. Also we researched whole your

corporate network and downloaded all

your sensitive data to our servers. If we will not get any contact

from you in the next 3 days we will public

it in our news site.

You can find it there (

https[:]// cuba4ikm4jakjgmkeztyawtdgr2xymvy6nvgw5cglswg3si76icnqd.onion/ )

Tor Browser is needed ( https[:]//www.torproject.org/download/ )

Also we respect your work and time and we are open for communication.

In that case we are ready to discuss

recovering your files and work. We can grant absolute privacy and

compliance with agreements by our side.

Also we can provide all necessary evidence to confirm performance of

our products and statements.

Feel free to contact us with quTox ( https[:]//tox.chat/download.html )

Our ToxID: 37790E2D198DFD20C9D2887D4EF7C3E295188842480192689864DCCA3C8BD808A18956768271

Alternative method is email: [email protected][.]net

Mark your messages with your personal ID:

---

Additional resources to detect possible exploitation or compromise:

• Palo Alto Networks Novel News on Cuba Ransomware: Greetings From Tropical Scorpius
• BlackBerry blog RomCom Threat Actor Abuses KeePass and SolarWinds to Target Ukraine and Potentially the United Kingdom
• BlackBerry blog Unattributed RomCom Threat Actor Spoofing Popular Apps Now Hits Ukrainian Militaries

MITRE ATT&CK TECHNIQUES

Cuba ransomware actors use the ATT&CK techniques listed in Table 6. Note: For details on TTPs listed in the table, see FBI Flash Indicators of Compromise Associated with Cuba Ransomware.

Resource Development

---

Technique Title

|

ID

|

Use

Compromise Infrastructure: Domains

|

T1584.001

|

Cuba ransomware actors use compromised networks to conduct their operations.

Initial Access

Technique Title

|

ID

|

Use

Valid Accounts

|

T1078

|

Cuba ransomware actors have been known to use compromised credentials to get into a victim’s network.

External Remote Services

|

T1133

|

Cuba ransomware actors may leverage external-facing remote services to gain initial access to a victim’s network.

Exploit Public-Facing Application

|

T1190

|

Cuba ransomware actors are known to exploit vulnerabilities in public-facing systems.

Phishing

|

T1566

|

Cuba ransomware actors have sent phishing emails to obtain initial access to systems.

Execution

Technique Title

|

ID

|

Use

Command and Scripting Interpreter: PowerShell

|

T1059.001

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Cuba ransomware actors have used PowerShell to escalate privileges.

Software Deployment Tools

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T1072

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Cuba ransomware actors use Hancitor as a tool to spread malicious files throughout a victim’s network.

Privilege Escalation

Technique Title

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ID

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Use

Exploitation for Privilege Escalation

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T1068

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Cuba ransomware actors have exploited ZeroLogon to gain administrator privileges.[2]

Defense Evasion

Technique Title

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ID

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Use

Impair Defenses: Disable or Modify Tools

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T1562.001

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Cuba ransomware actors leveraged a loader that disables security tools within the victim network.

Lateral Movement

Technique Title

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ID

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Use

Remote Services Session: RDP Hijacking

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T1563.002

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Cuba ransomware actors used RDP sessions to move laterally.

Credential Access

Technique Title

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ID

|

Use

Credential Dumping: LSASS Memory

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T1003.001

|

Cuba ransomware actors use LSASS memory to retrieve stored compromised credentials.

Steal or Forge Kerberos Tickets: Kerberoasting

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T1558.003

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Cuba ransomware actors used the Kerberoasting technique to identify service accounts linked to active directory.[2]

Command and Control

Technique Title

|

ID

|

Use

Proxy: Manipulate Command and Control Communications

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T1090

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Industrial Spy ransomware actors use HTTP/HTTPS proxy via a C2 server to direct traffic to avoid direct connection. [2]

Mitigations

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 Cuba 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). JIT sets a network-wide policy 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

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 ransomware actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file.

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, FBI and CISA urge you to promptly report ransomware incidents immediately. Report to a local FBI Field Office, or CISA at us-cert.cisa.gov/report.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI and CISA 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 FBI or CISA.

ACKNOWLEDGEMENTS

FBI and CISA would like to thank BlackBerry, ESET, The National Cyber-Forensics and Training Alliance (NCFTA), Palo Alto Networks, and PRODAFT for their contributions to this CSA.

References

[1] Palo Alto Networks: Tropical Scorpius

[2] Palo Alto Networks: Novel News on Cuba Ransomware - Greetings From Tropical Scorpius

[3] BlackBerry: Unattributed RomCom Threat Actor Spoofing Popular Apps Now Hits Ukrainian Militaries

[4] BlackBerry: RomCom Threat Actor Abuses KeePass and SolarWinds to Target Ukraine and Potentially the United Kingdom

Revisions

December 1, 2022: Initial Version|December 12, 2022: Added new IP addresses and IOCs