Threat Signal Report

New Conti Ransomware Campaign Observed in the Wild

description-logo Description

FortiGuard Labs has observed a new wave of ransomware threats belonging to the Conti malware family, active in Mexico. These variants appear to target the latest Linux and ESX systems and enable the attacker to encrypt files on the victim's machine and guest virtual machines. The variants are all dynamically linked 64-bit ELF samples written in C.

A similar sample to the ones in this campaign was documented previously by Trellix.



Why is this Significant?
This is significant because the newly observed campaign was launched by the Conti ransomware group who are known for taking encrypted files and stolen information belonging to countless companies from varying sectors hostage for profits. The group announced it plans to retaliate against western targets after the Russian invasion into Ukraine adding a political motivation on top of financial gain.

This new campaign seems to be similar to the previous campaigns however, some of the samples involved have much lower detection rates at the time of this writing.





What Does the Malware Do?
Conti ransomware variants used in the new campaign performs activities identical to the previous ones; it encrypts files on the compromised machine and adds a ".conti" file extension to them after the threat actor exfiltrates information from victim's network. It will then demand a ransom payment from the victim in order to recover the affected files and to prevent stolen information from being released to the public.

It leaves a ransom note that reads:

All of your files are currently encrypted by CONTI strain. If you don't know who we are - just "Google it".

As you already know, all of your data has been encrypted by our software. It cannot be recovered by any means without contacting our team directly.

DONT'T TRY TO RECOVER your data by yourselves. Any attempt to recover your data (including the usage of the additional recovery software) can damage your files. However, if you want to try - we recommend choosing the data of the lowest value.

DON'T TRY TO IGNORE us. We've downloaded a pack of your internal data and are ready to publich it on our news website if you do not respond. So it will be better for both sides if you contact us as soon as possible.

DON'T TRY TO CONTACT feds or any recovery companies.
We have our informants in these as a hostile intent and initiate the publication of whole compromised data immediatly.

To prove that we REALLY CAN get your data back - we offer you to decrypt two random files completely free of charge.

You can contact our team directly for further instructions through our website :
TOR VERSION :
(you should download and install TOR browser first hxxps://torproject[.]org)
hxxp://[Removed].onion/

YOU SHOULD BE AWARE
We will speak only with an authorized person. It can be the CEO, top management, etc.
In case you are not such a person - DON'T CONTACT US
Your decisions and action can result in serious harm to your company
Inform your supervisors and stay calm


The malware can also be run on ESX environments and has the ability to shut down and encrypt the associated virtual machines.


The malware has a detailed helper dialog. This provides another indication for the fact Conti group consists of many people.




What is the Status of Coverage?
FortiGuard Labs provides the following AV signatures for the Conti ransomware samples observed in the new campaign:


  • Linux/Filecoder_Conti.083E!tr.ransom
  • Linux/Filecoder_Conti.0B97!tr.ransom
  • Linux/Filecoder_Conti.14E3!tr.ransom
  • Linux/Filecoder_Conti.3233!tr.ransom
  • Linux/Filecoder_Conti.3691!tr.ransom
  • Linux/Filecoder_Conti.3FA2!tr.ransom
  • Linux/Filecoder_Conti.5DE1!tr.ransom
  • Linux/Filecoder_Conti.638B!tr.ransom
  • Linux/Filecoder_Conti.65AB!tr.ransom
  • Linux/Filecoder_Conti.919D!tr.ransom
  • Linux/Filecoder_Conti.BDC5!tr.ransom
  • Linux/Filecoder_Conti.C2F5!tr.ransom
  • Linux/Filecoder_Conti.C3D1!tr.ransom
  • Linux/Filecoder_Babyk.H!tr
  • PossibleThreat


FortiEDR blocks the Conti samples pre-execution.

Appendix

Conti Group Targets ESXi Hypervisors With its Linux Variant (Trellix)


IOCs

35ea625eb99697efdeb016192b25c5323ec10b0b33642cd9b2641e058e5e8dc6

8b57e96e90cd95fc2ba421204b482005fe41c28f506730b6148bcef8316a3201

0b188a6915aa7be71b224ef8a43795939bd90a44ba5818c644c1250e2e4c9a87

0780d010b8253a527796a0a078d0b15cf1862b75ecf0005028731c01d67d3f8b

8a07e896dc9273339bc895b2cc200cc856678bf25777c9acb79fb5f7bf7f3461

07174ea58d020596d467951591091435e4ee13f1dbb1dd033938acb1b7da772f

04b74b60222a795326d6e362026ea78602297655a316ff9521d5c0e333c9a005

67b96ba4d6d603ae7dee2882f605dd4e1fe38be1e46d9c8a8097af410fe34aa4

e863b3dcf6b7de76e34fcb990463830bc5810269937c5a32545cc059ab7da089

8b719b94dd3cea0da2f5571c5a7d5f3a05e9be623401174a7e75fbb7a2c0e699

393ccb61c378356a95cd3030a7609b9011f023790a9ac9fbd5ff0ecfce7bf925

cfdbdf019ae71d72e68a41744398ca85c1ab65b22c30e8432ffa165850804c47

13fa3e25f69c4e0c8f79208b8ab227d8a43df72b458b4825190d05697656d907

c7c5086378f1f12dbddb0a3ae88ee401dd7492040bee84498dcb271822b4bb86

daa7ee253e4bb7427dc6ba095d8ab0cba11e380b05f576b1997dfe11dff23e01

eb2b667d226813eafaf89ccab99a8a44a1da44647a0ab69c57b3dc21ead287bb

81f3e7a8ff6605e50e46ae837029a50572bdf0060ecc6a865c6ac910e5633efd


YARA Rule

rule crime_RU_Conti_locker_Sep22 {

meta:

Author="FortiEDR Research Group"

        date="04/09/22"

strings:

$a1 = "\x00_Z13EncryptPartly"

$a2 = "\x00_Z11EncryptFullP9file_info"

$a3 = "\x00_Z11EncryptFile"

$a4 = "\x00_Z16WriteEncryptInfoP9file_info"

$a5 = "\x00_Z19KillVirtualMachines"

$a6 = "\x00_Z14GetDecryptNote"

$a7 = "Cannot create file vm-list.txt\x00"

$a8 = "http://contirec.poc.onion/-"

$a9 = "D90IXnZbm2xF5enn2UtGv9yFDoufSvFTAs2524xqqx"

$a10 = "All of your files are currently encrypted by CONTI strain." 

$a11 = "DON'T TRY TO CONTACT feds or any recovery companies" 

$a12 = "fork() error in GetVMList(). errno = %d\x0A\x00"


$b1 = "Cannot rename file %s\x0A\x00"

$b2 = "\x00--world-id=%d\x00"

$b3 = "\x00Cannot alloc memory\x00"

$b4 = "\x00Cannot opendir %s errno = %d\x0A\x00"

$b5 = ".conti\x00"


$c1 = {89 ?? ?? 8? ?? ?? ?? 01 ?? C? ?? 2E 63 6F 6E ?? C? ?? 04 74 69}

$c2 = {B? 2F 43 4F 4E 54 49 5F 52 ?? B? 45 41 44 4D 45 2E 74 78}

condition:

uint32(0) == 0x464c457f and (

2 of ($a*) or 

3 of ($b*) or (

any of ($a*, $b*) and 

any of ($c*)

)

)

}



Definitions

Traffic Light Protocol

Color When Should it Be used? How may it be shared?

TLP: RED

Not for disclosure, restricted to participants only.
Sources may use TLP:RED when information cannot be effectively acted upon by additional parties, and could lead to impacts on a party's privacy, reputation, or operations if misused. Recipients may not share TLP:RED information with any parties outside of the specific exchange, meeting, or conversation in which it was originally disclosed. In the context of a meeting, for example, TLP:RED information is limited to those present at the meeting. In most circumstances, TLP:RED should be exchanged verbally or in person.

TLP: AMBER

Limited disclosure, restricted to participants’ organizations.
Sources may use TLP:AMBER when information requires support to be effectively acted upon, yet carries risks to privacy, reputation, or operations if shared outside of the organizations involved. Recipients may only share TLP:AMBER information with members of their own organization, and with clients or customers who need to know the information to protect themselves or prevent further harm. Sources are at liberty to specify additional intended limits of the sharing: these must be adhered to.

TLP: GREEN

Limited disclosure, restricted to the community.
Sources may use TLP:GREEN when information is useful for the awareness of all participating organizations as well as with peers within the broader community or sector. Recipients may share TLP:GREEN information with peers and partner organizations within their sector or community, but not via publicly accessible channels. Information in this category can be circulated widely within a particular community. TLP:GREEN information may not be released outside of the community.

TLP: WHITE

Disclosure is not limited.
Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction.