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The Cybersecurity and Infrastructure Security Agency (CISA), the Federal Bureau of Investigation (FBI), the Multi-State Information Sharing and Analysis Center (MS-ISAC), and the Canadian Centre for Cyber Security (CCCS) are releasing this joint Cybersecurity Advisory (CSA) in response to cyber threat actors leveraging newly identified Truebot malware variants against organizations in the United States and Canada. As recently as May 31, 2023, the authoring organizations have observed an increase in cyber threat actors using new malware variants of Truebot (also known as Silence.Downloader). Truebot is a botnet that has been used by malicious cyber groups like CL0P Ransomware Gang to collect and exfiltrate information from its target victims.
Previous Truebot malware variants were primarily delivered by cyber threat actors via malicious phishing email attachments; however, newer versions allow cyber threat actors to also gain initial access through exploiting CVE-2022-31199—(a remote code execution vulnerability in the Netwrix Auditor application), enabling deployment of the malware at scale within the compromised environment. Based on confirmation from open-source reporting and analytical findings of Truebot variants, the authoring organizations assess cyber threat actors are leveraging both phishing campaigns with malicious redirect hyperlinks and CVE-2022-31199 to deliver new Truebot malware variants.
The authoring organizations recommend hunting for the malicious activity using the guidance outlined in this CSA, as well as applying vendor patches to Netwrix Auditor (version 10.5—see Mitigations section below).[1] Any organization identifying indicators of compromise (IOCs) within their environment should urgently apply the incident responses and mitigation measures detailed in this CSA and report the intrusion to CISA or the FBI.
Download the PDF version of this report:
Read the associated Malware Analysis Report MAR-10445155-1.v1 Truebot Activity Infects U.S. and Canada Based Networks or download the PDF version below:
For a downloadable copy of IOCs in .xml and .json format, see:
Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 13. See the MITRE ATT&CK Tactics and Techniques section below for cyber threat actors’ activity mapped to MITRE ATT&CK tactics and techniques.
In recent months, open source reporting has detailed an increase in Truebot malware infections, particularly cyber threat actors using new tactics, techniques, and procedures (TTPs), and delivery methods.[2] Based on the nature of observed Truebot operations, the primary objective of a Truebot infection is to exfiltrate sensitive data from the compromised host(s) for financial gain [TA0010].
Following the successful download of the malicous file, Truebot renames itself and then loads FlawedGrace onto the host. Please see the FlawedGrace section below for more information on how this remote access tool (RAT) is used in Truebot operations.
After deployment by Truebot, FlawedGrace is able to modify registry [T1112] and print spooler programs [T1547.012] that control the order that documents are loaded to a print queue. FlawedGrace manipulates these features to both escalate privilege and establish persistence.
During FlawedGrace’s execution phase, the RAT stores encrypted payloads [T1027.009] within the registry. The tool can create scheduled tasks and inject payloads into msiexec[.]exe and svchost[.]exe, which are command processes that enable FlawedGrace to establish a command and control (C2) connection to 92.118.36[.]199, for example, as well as load dynamic link libraries (DLLs) [T1055.001] to accomplish privilege escalation.
Several hours post initial access, Truebot has been observed injecting Cobalt Strike beacons into memory [T1055] in a dormant mode for the first few hours prior to initiating additional operations. Please see the Cobalt Strike section below for more information on how this remote access tool (RAT) is used in Truebot operations.
During the first stage of Truebot’s execution process, it checks the current version of the operating system (OS) with RtlGetVersion and processor architecture using GetNativeSystemInfo [T1082].[4] Note: This variant of Truebot malware is designed with over one gigabyte (GB) of junk code which functions to hinder detection and analysis efforts [T1027.001].
Following the initial checks for system information, Truebot has the capability to enumerate all running processes [T1057], collect sensitive local host data [T1005], and send this data to an encoded data string described below for second-stage execution. Based on IOCs in table 1, Truebot also has the ability to discover software security protocols and system time metrics, which aids in defense evasion, as well as enables synchronization with the compromised system’s internal clock to facilitate scheduling tasks [T1518.001][T1124].
Next, it uses a .JSONIP extension, (e.g., IgtyXEQuCEvAM.JSONIP), to create a thirteen character globally unique identifier (GUID)—a 128-bit text string that Truebot uses to label and organize the data it collects [T1036].
After creating the GUID, Truebot compiles and enumerates running process data into either a base64 or unique hexadecimal encoded string [T1027.001]. Truebot’s main goal is identifying the presence of security debugger tools. However, the presence of identified debugger tools does not change Truebot’s execution process—the data is compiled into a base64 encoded string for tracking and defense evasion purposes [T1082][T1622].
Following Truebot’s enumeration of running processes and tools, the affected system’s computer and domain name [T1082][T1016], along with the newly generated GUID, are sent to a hard-coded URL in a POST request (as observed in the user-agent string). Note: A user-agent string is a customized HTTP request that includes specific device information required for interaction with web content. In this instance, cyber threat actors can redirect victims to malicious domains and further establish a C2 connection.
The POST request functions as means for establishing a C2 connection for bi-lateral communication. With this established connection, Truebot uses a second obfuscated domain to receive additional payloads [T1105], self-replicate across the environment [T1570], and/or delete files used in its operations [T1070.004]. Truebot malware has the capability to download additional malicious modules [T1105], load shell code [T1620], and deploy various tools to stealthily navigate an infected network.
Truebot has been observed in association with the following delivery vectors and tools:
Raspberry Robin is a wormable malware with links to other malware families and various infection methods, including installation via USB drive [T1091].[5] Raspberry Robin has evolved into one of the largest malware distribution platforms and has been observed deploying Truebot, as well as other post-compromise payloads such as IcedID and Bumblebee malware.[6] With the recent shift in Truebot delivery methods from malicious emails to the exploitation of CVE-2022-31199, a large number of Raspberry Robin infections have leveraged this exploitable CVE.[2]
FlawedGrace is a remote access tool (RAT) that can receive incoming commands [T1059] from a C2 server sent over a custom binary protocol [T1095] using port 443 to deploy additional tools [T1105].[7] Truebot malware has been observed leveraging (and dropping) FlawedGrace via phishing campaigns as an additional payload [T1566.002].[8] Note: FlawedGrace is typically deployed minutes after Truebot malware is executed.
Cobalt Strike is a popular remote access tool (RAT) that cyber threat actors have leveraged—in an observable manner—for a variety of post-exploitation means. Typically a few hours after Truebot’s execution phase, cyber threat actors have been observed deploying additional payloads containing Cobalt Strike beacons for persistence and data exfiltration purposes [T1059].[2] Cyber threat actors use Cobalt Strike to move laterally via remote service session hijacking [T1563.001][T1563.002], collecting valid credentials through LSASS memory credential dumping, or creating local admin accounts to achieve pass the hash alternate authentication [T1003.001][T1550.002].
Cyber threat actors have been observed using a custom data exfiltration tool, which Talos has named “Teleport.”[2] Teleport is known to evade detection during data exfiltration by using an encryption key hardcoded in the binary and a custom communication protocol [T1095] that encrypts data using advanced encryption standard (AES) and a hardcoded key [T1048][T1573.002]. Furthermore, to maintain its stealth, Teleport limits the data it collects and syncs with outbound organizational data/network traffic [T1029][T1030].
Truebot IOCs from May 31, 2023, contain IOCs from cyber threat actors conducting Truebot malspam campaigns. Information is derived from a trusted third party, they observed cyber threat actors from 193.3.19[.]173 (Russia) using a compromised local account to conduct phishing campaigns on May 23, 2023 and spread malware through: https[:]//snowboardspecs[.]com/nae9v, which then promptly redirects the user to: https://www.meditimespharma[.]com/gfghthq/, which a trusted third party has linked to other trending Truebot activity.
After redirecting to https://www.meditimespharma[.]com/gfghthq/, trusted third parties have observed, the cyber threat actors using Truebot to pivot to https://corporacionhardsoft[.]com/images/2/Document_16654.exe, which is a domain associated with snowboardspecs[.]com. This malicious domain has been linked to UNC4509, a threat cluster that has been known to use traffic distribution systems (TDS) to redirect users to either a benign or malicious website to facilitate their malicious phishing campaigns in May 2023.
According to trusted third parties, the MD5 Hash: 6164e9d297d29aa8682971259da06848 is downloaded from https://corporacionhardsoft.com/images/2/Document_16654[.]exe, and has been flagged by numerous security vendors, as well as is linked to UNC4509 Truebot campaigns. Note: These IOCs are associated with Truebot campaigns used by Graceful Spider to deliver FlawedGrace and LummaStealer payloads in May of 2023.
After Truebot is downloaded, the malware copies itself to C:IntelRuntimeBroker.exe and—based on trusted third party analysis—links to https://essadonio.com/538332[.]php (which is linked to 45.182.189[.]71 (Panama) and is associated with other trending Truebot malware campaigns from May 2023).
Please reference table 1 for IOCs described in the paragraph above.
Indicator Type
Indicator
Source
Registrant
GKG[.]NET Domain Proxy Service Administrator
Trusted Third Party
Compromised Account Created:
2022-04-10
Trusted Third Party
Malicious account created
1999-11-09
Trusted Third Party
IP
193.3.19[.]173 (Russia)
Trusted Third Party
URL
https://snowboardspecs[.]com/nae9v
Trusted Third Party
Domain
https://corporacionhardsoft[.]com/images/2/Document_16654.exe
Trusted Third Party
File
Document_16654[.]exe
Trusted Third Party
MD5 Hash
6164e9d297d29aa8682971259da06848
Trusted Third Party
File
Document_may_24_16654[.]exe
Trusted Third Party
File
C:IntelRuntimeBroker[.]exe
Trusted Third Party
URL
https://essadonio.com/538332[.]php
Trusted Third Party
IP
45.182.189[.]71 (Panama)
Trusted Third Party
Account Created
2023-05-18
Trusted Third Party
Indicator Type
Indicator
Source
File Name
Secretsdump[.]py
Domain
Imsagentes[.]pe
URL
https://imsagentes[.]pe/dgrjfj/
URL
https://imsagentes[.]pe/dgrjfj
URL
https://hrcbishtek[.]com/{5
URL
https://ecorfan.org/base/sj/document_may_24_16654[.]exe
Domain
Hrcbishtek[.]com
MD5 Hash
F33734DFBBFF29F68BCDE052E523C287
MD5 Hash
F176BA63B4D68E576B5BA345BEC2C7B7
MD5 Hash
F14F2862EE2DF5D0F63A88B60C8EEE56
Domain
Essadonio[.]com
Domain
Ecorfan[.]org
SHA256 Hash
C92C158D7C37FEA795114FA6491FE5F145AD2F8C08776B18AE79DB811E8E36A3
File Name
Atexec[.]py
MD5 Hash
A0E9F5D64349FB13191BC781F81F42E1
IPv4
92.118.36[.]199
IPv4
81.19.135[.]30
MD5 Hash
72A589DA586844D7F0818CE684948EEA
SHA256 Hash
717BEEDCD2431785A0F59D194E47970E9544FBF398D462A305F6AD9A1B1100CB
IPv4
5.188.86[.]18
IPv4
5.188.206[.]78
IPv4
45.182.189[.]71
IPv4
139.60.160[.]166
SHA256 Hash
121A1F64FFF22C4BFCEF3F11A23956ED403CDEB9BDB803F9C42763087BD6D94E
nitutdra[.]com
46.161.40[.]128
romidonionhhgtt[.]com
46.161.40.128
midnigthwaall[.]com
46.161.40[.]128
dragonetzone[.]com
46.161.40[.]128
hxxps://dragonetzone[.]com/gate_info[.]php
rprotecruuio[.]com
45.182.189[.]71
essadonio[.]com
45.182.189[.]71
hxxps://nomoresense[.]com/checkinfo[.]php
nomoresense[.]com
45.182.189[.]91
hxxps://nomoresense[.]com/checkinfo[.]php
ronoliffuion[.]com
45.182.189[.]120
hxxps://ronoliffuion[.]com/dns[.]php
bluespiredice[.]com
45.182.189[.]119
dremmfyttrred[.]com
45.182.189[.]103
hxxps://dremmfyttrred[.]com/dns[.]php
ms-online-store[.]com
45.227.253[.]102
ber6vjyb[.]com
92.118.36[.]252
hxxps://ber6vjyb[.]com/dns[.]php
jirostrogud[.]com
88.214.27[.]101
hxxps://ber6vjyb[.]com/dns[.]php
fuanshizmo[.]com
45.182.189[.]229
qweastradoc[.]com
92.118.36[.]213
hxxp://nefosferta[.]com/gate[.]php
qweastradoc[.]com
92.118.36[.]213
hxxp://nefosferta[.]com/gate[.]php
qweastradoc[.]com
92.118.36[.]213
hxxp://nefosferta[.]com/gate[.]php
hiperfdhaus[.]com
88.214.27[.]100
hxxp://nefosferta[.]com/gate[.]php
guerdofest[.]com
45.182.189[.]228
hxxp://qweastradoc[.]com/gate[.]php
nefosferta[.]com
179.60.150[.]139
hxxp://nefosferta[.]com/gate[.]php
Malicious Domain
MD5
SHA1
SHA256
nitutdra[.]com
romidonionhhgtt[.]com
midnigthwaall[.]com
dragonetzone[.]com
64b27d2a6a55768506a5658a31c045de
c69f080180430ebf15f984be14fb4c76471cd476
e0178ab0893a4f25c68ded11e74ad90403443e413413501d138e0b08a910471e
rprotecruuio[.]com
essadonio[.]com
9a3bad7d8516216695887acc9668cda1
a89c097138e5aab1f35b9a03900600057d907690
4862618fcf15ba4ad15df35a8dcb0bdb79647b455fea6c6937c7d050815494b0
essadonio[.]com
6164e9d297d29aa8682971259da06848
96b95edc1a917912a3181d5105fd5bfad1344de0
717beedcd2431785a0f59d194e47970e9544fbf398d462a305f6ad9a1b1100cb
nomoresense[.]com
8f924f3cbe5d8fe3ecb7293478901f1a
516051b4cab1be74d32a6c446eabac7fc354904f
6b646641c823414c2ee30ae8b91be3421e4f13fa98e2d99272956e61eecfc5a1
nomoresense[.]com
ac6a2f1eafaae9f6598390d1017dd76c
1c637c2ded5d3a13fd9b56c35acf4443f308be52
f9f649cb5de27f720d58aa44aec6d0419e3e89f453730e155067506ad3ece638
ronoliffuion[.]com
881485ac77859cf5aaa8e0d64fbafc5f
51be660a3bdaab6843676e9d3b2af8444e88bbda
36d89f0455c95f9b00a8cea843003d0b53c4e33431fe57b5e6ec14a6c2e00e99
bluespiredice[.]com
dremmfyttrred[.]com
e4a42cbda39a20134d6edcf9f03c44ed
afda13d5365b290f7cdea701d00d05b0c60916f8
47f962063b42de277cd8d22550ae47b1787a39aa6f537c5408a59b5b76ed0464
dremmfyttrred[.]com
aa949d1a7ebe5f878023c6cfb446e29b
06057d773ad04fda177f6b0f6698ddaa47f7168a
594ade1fb42e93e64afc96f13824b3dbd942a2cdbc877a7006c248a38425bbc1
dremmfyttrred[.]com
338476c2b0de4ee2f3e402f3495d0578
03916123864aa034f7ca3b9d45b2e39b5c91c502
a67df0a8b32bdc5f9d224db118b3153f66518737e702314873b673c914b2bb5c
ms-online-store[.]com
ber6vjyb[.]com
46fe07c07fd0f45ba45240ef9aae2a44
b918f97c7c6ebc9594de3c8f2d9d75ecc292d02b
c0f8aeeb2d11c6e751ee87c40ee609aceb1c1036706a5af0d3d78738b6cc4125
jirostrogud[.]com
89c8afc5bbd34f160d8a2b7218b9ca4a
16ecf30ff8c7887037a17a3eaffcb17145b69160
5cc8c9f2c9cee543ebac306951e30e63eff3ee103c62dadcd2ce43ef68bc7487
jirostrogud[.]com
5da364a8efab6370a174736705645a52
792623e143ddd49c36f6868e948febb0c9e19cd3
80b9c5ec798e7bbd71bbdfffab11653f36a7a30e51de3a72c5213eafe65965d9
fuanshizmo[.]com
qweastradoc[.]com
ee1ccb6a0e38bf95e44b73c3c46268c5
62f5a16d1ef20064dd78f5d934c84d474aca8bbe
0e3a14638456f4451fe8d76fdc04e591fba942c2f16da31857ca66293a58a4c3
qweastradoc[.]com
82d4025b84cf569ec82d21918d641540
bb32c940f9ca06e7e8533b1d315545c3294ee1a0
c042ad2947caf4449295a51f9d640d722b5a6ec6957523ebf68cddb87ef3545c
qweastradoc[.]com
dbecfe9d5421d319534e0bfa5a6ac162
9e7a2464f53ce74d840eb84077472bc29fd1ba05
c9b874d54c18e895face055eeb6faa2da7965a336d70303d0bd6047bec27a29d
qweastradoc[.]com
b7fed593e8eb3646f876367b56725e6c
44090a7858eceb28bc111e1edd2f0dc98047afb2
ff8c8c8bfba5f2ba2f8003255949678df209dbff95e16f2f3c338cfa0fd1b885
hiperfdhaus[.]com
8e2b823aac6c9e11fcabecb1d8c19adf
77ad34334a370d85ca5e77436ed99f18b185eee3
a30e1f87b78d1cd529fbe2afdd679c8241d3baab175b2f083740263911a85304
hiperfdhaus[.]com
8a94163ddf956abd0ea92d89db0034e5
abc96032071adeb6217f0a5ba1aff55dc11f5438
b95a764820e918f42b664f3c9a96141e2d7d7d228da0edf151617fabdd9166cf
guerdofest[.]com
65fb9572171b903aa31a325f550d8778
d8bd44b7a8f136e29b31226f4edf566a4223266c
d5bbcaa0c3eeea17f12a5cc3dbcaffff423d00562acb694561841bcfe984a3b7
nefosferta[.]com
d9d85bdb6a3ac60a8ba6776c661dbace
78e38e522b1765efb15d0585e13c1f1301e90788
092910024190a2521f21658be849c4ac9ae6fa4d5f2ecd44c9055cc353a26875
nefosferta[.]com
20643549f19bed9a6853810262622755
c8227dcc1cd6ecc684de8c5ea9b16e3b35f613f1
1ef8cdbd3773bd82e5be25d4ba61e5e59371c6331726842107c0f1eb7d4d1f49
nefosferta[.]com
e9299fc9b7daa0742c28bfc4b03b7b25
77360abc473dc65c8bdd73b6459b9ea8fddb6f1d
22e3f4602a258e92a0b8deb5a2bd69c67f4ac3ca67362a745178848a9da7a3cc
nefosferta[.]com
775fb391db27e299af08933917a3acda
eaaa5e68956a3a3f6113e965199f479e10ae9956
2d50b03a92445ba53ae147d0b97c494858c86a56fe037c44bc0edabb902420f7
nefosferta[.]com
f4045710c99d347fe6dfa2c0fcadde29
b7bffdbbaf817d149bbd061070a2d171449afbfc
32ae88cddeeeec255d6d9c827f6bffc7a95e9ea7b83a84a79ff793735a4b4ed7
nefosferta[.]com
587acecdb9491e0897d1067eb02e7c8d
a9eb1ac4b85d17da3a2bae5835c7e862d481c189
55d1480cd023b74f10692c689b56e7fd6cc8139fb6322762181daead55a62b9e
nefosferta[.]com
0bae65245e5423147fce079de29b6136
f24232330e6f428bfbb6b9d8154db1c4046c2fc2
6210a9f5a5e1dc27e68ecd61c092d2667609e318a95b5dade3c28f5634a89727
nefosferta[.]com
5022a85b39a75ebe2bc0411d7b058b2e
a9040ac0e9f482454e040e2a7d874ddc50e6f6ce
68a86858b4638b43d63e8e2aaec15a9ebd8fc14d460dd74463db42e59c4c6f89
nefosferta[.]com
6a2f114a8995dbeb91f766ac2390086e
edac3cf9533b6f7102f6324fadb437a0814cc680
72813522a065e106ac10aa96e835c47aa9f34e981db20fa46a8f36c4543bb85d
nefosferta[.]com
e9115cc3280c16f9019e0054e059f4b8
dad01b0c745649c6c8b87dbeb7ab549ed039515d
7a64bc69b60e3cd3fd00d4424b411394465640f499e56563447fe70579ccdd00
nefosferta[.]com
b54cc9a3dd88e478ea601dfd5b36805e
318fdfec4575d1530a41c80274aa8caae7b7f631
7c607eca4005ba6415e09135ef38033bb0b0e0ff3e46d60253fc420af7519347
nefosferta[.]com
f129c12b1bda7426f6b31682b42ee4b0
5bb804153029c97fe23517ae5428a591c3c63f28
7c79ec3f5c1a280ffdf19d0000b4bfe458a3b9380c152c1e130a89de3fe04b63
nefosferta[.]com
f68aa4c92dd30bd5418f136aaf6c07d6
aa56f43e39d114235a6b1d5f66b593cc80325fa4
7e39dcd15307e7de862b9b42bf556f2836bf7916faab0604a052c82c19e306ca
nefosferta[.]com
acac995cee8a6a75fa79eb41bdffa53f
971a00a392b99f64a3886f40b6ef991e62f0fe2f
97bae3587f1d2fd35f24eb214b9dd6eed95744bed62468d998c7ef55ff8726d4
nefosferta[.]com
36057710279d9f0d023cb5613aa76d5e
e4dd1f8fc4e44c8fd0e25242d994c4b59eed6939
97d0844ce9928e32b11706e06bf2c4426204d998cb39964dd3c3de6c5223fff0
nefosferta[.]com
37e6904d84153d1435407f4669135134
1dcd85f7364ea06cd595a86e3e9be48995d596e9
bf3c7f0ba324c96c9a9bff6cf21650a4b78edbc0076c68a9a125ebcba0e523c9
nefosferta[.]com
4f3916e7714f2a32402c9d0b328a2c91
87a692e3592f7b997c7d962919e243b665f2be36
c3743a8c944f5c9b17528418bf49b153b978946838f56e5fca0a3f6914bee887
nefosferta[.]com
d9daaa0df32b0bb01a09e500fc7f5881
f9cb839adba612db5884e1378474996b4436c0cd
c3b3640ddf53b26f4ebd4eedf929540edb452c413ca54d0d21cc405c7263f490
nefosferta[.]com
c87fb9b9f6c343670bed605420583418
f05cf0b026b2716927dac8bcd26a2719ea328964
c6c4f690f0d15b96034b4258bdfaf797432a3ec4f73fbc920384d27903143cb0
nefosferta[.]com
2be64efd0fa7739123b26e4b70e53c5c
318fdfec4575d1530a41c80274aa8caae7b7f631
ed38c454575879c2546e5fccace0b16a701c403dfe3c3833730d23b32e41f2fe
Malicious Domain
IP Addresses
Files
SHA256
Dremmfyttrred[.]com
45.182.189[.]103
94.142.138[.]61
172.64.155[.]188
104.18.32[.]68
Update[.]exe
Document_26_apr_2443807[.]exe
3ujwy2rz7v[.]exe
fe746402c74ac329231ae1b5dffa8229b509f4c15a0f5085617f14f0c1579040
droogggdhfhf[.]com
3LXJyA6Gf[.]exe
7d75244449fb5c25d8f196a43a6eb9e453652b2185392376e7d44c21bd8431e7
See Tables 6-16 for all referenced cyber threat actor tactics and techniques for enterprise environments in this advisory. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.
Technique Title
ID
Use
Replication Through Removable Media
T1091
Cyber threat actors use removable media drives to deploy Raspberry Robin malware.
Drive-by Compromise
T1189
Cyber threat actors embed malicious links or attachments within web domains to gain initial access.
Exploit Public-Facing Application
T1190
Cyber threat actors are exploiting Netwrix vulnerability CVE-2022-31199 for initial access with follow-on capabilities of lateral movement through remote code execution.
Phishing
T1566.002
Truebot actors can send spear phishing links to gain initial access.
Technique Title
ID
Use
Command and Scripting Interpreter
T1059
Cyber threat actors have been observed dropping cobalt strike beacons as a reverse shell proxy to create persistence within the compromised network.
Cyber threat actors use FlawedGrace to receive PowerShell commands over a C2 channel to deploy additional tools.
Shared Modules
T1129
Cyber threat actors can deploy malicious payloads through obfuscated share modules.
User Execution: Malicious Link
T1204.001
Cyber threat actors trick users into clicking a link by making them believe they need to perform a Google Chrome software update.
Technique Title
ID
Use
Hijack Execution Flow: DLL Side-Loading
1574.002
Cyber threat actors use Raspberry Robin, among other toolsets to side-load DLLs to maintain persistence.
Technique Title
ID
Use
Boot or Logon Autostart Execution: Print Processors
T1547.012
FlawedGrace malware manipulates print spooler functions to achieve privilege escalation.
Technique Title
ID
Use
Obfuscated Files or Information
T1027
Truebot uses a .JSONIP extension (e.g., IgtyXEQuCEvAM.JSONIP), to create a GUID.
Obfuscated Files or Information: Binary Padding
T1027.001
Cyber threat actors embed around one gigabyte of junk code within the malware string to evade detection protocols.
Masquerading: Masquerade File Type
T1036.008
Cyber threat actors hide Truebot malware as legitimate appearing file formats.
Process Injection
T1055
Truebot malware has the ability to load shell code after establishing a C2 connection.
Indicator Removal: File Deletion
T1070.004
Truebot malware implements self-deletion TTPs throughout its attack cycle to evade detection.
Teleport exfiltration tool deletes itself after it has completed exfiltrating data to the C2 station.
Modify Registry
T1112
FlawedGrace is able to modify registry programs that control the order that documents are loaded to a print que.
Reflective Code Loading
T1620
Truebot malware has the capability to load shell code and deploy various tools to stealthily navigate an infected network.
Technique Title
ID
Use
OS Credential Dumping: LSASS Memory
T1003.001
Cyber threat actors use cobalt strike to gain valid credentials through LSASS memory dumping.
Technique Title
ID
Use
System Network Configuration Discovery
T1016
Truebot malware scans and enumerates the affected system’s domain names.
Process Discovery
T1057
Truebot malware enumerates all running processes on the local host.
System Information Discovery
T1082
Truebot malware scans and enumerates the OS version information, and processor architecture.
Truebot malware enumerates the affected system’s computer names.
System Time Discovery
T1124
Truebot has the ability to discover system time metrics, which aids in enables synchronization with the compromised system’s internal clock to facilitate scheduling tasks.
Software Discovery: Security Software Discovery
T1518.001
Truebot has the ability to discover software security protocols, which aids in defense evasion.
Debugger Evasion
T1622
Truebot malware scans the compromised environment for debugger tools and enumerates them in effort to evade network defenses.
Technique Title
ID
Use
Exploitation of Remote Services
T1210
Cyber threat actors exploit CVE-2022-31199 Netwrix Auditor vulnerability and use its capabilities to move laterally within a compromised network.
Use Alternate Authentication Material: Pass the Hash
T1550.002
Cyber threat actors use cobalt strike to authenticate valid accounts
Remote Service Session Hijacking
T1563.001
Cyber threat actors use cobalt strike to hijack remote sessions using SSH and RDP hijacking methods.
Remote Service Session Hijacking: RDP Hijacking
T1563.002
Cyber threat actors use cobalt strike to hijack remote sessions using SSH and RDP hijacking methods.
Lateral Tool Transfer
T1570
Cyber threat actors deploy additional payloads to transfer toolsets and move laterally.
Technique Title
ID
Use
Data from Local System
T1005
Truebot malware checks the current version of the OS and the processor architecture and compiles the information it receives.
Truebot gathers and compiles compromised system’s host and domain names.
Screen Capture
T1113
Truebot malware takes snapshots of local host data, specifically processor architecture data, and sends that to a phase 2 encoded data string.
Technique Title
ID
Use
Application Layer Protocol
T1071
Cyber threat actors use teleport exfiltration tool to blend exfiltrated data with network traffic.
Non-Application Protocol
T1095
Cyber threat actors use Teleport and FlawedGrace to send data over custom communication protocol.
Ingress Transfer Tool
T1105
Cyber threat actors deploy various ingress transfer tool payloads to move laterally and establish C2 connections.
Encrypted Channel: Asymmetric Cryptography
T1573.002
Cyber threat actors use Teleport to create an encrypted channel using AES.
Technique Title
ID
Use
Scheduled Transfer
T1029
Teleport limits the data it collects and syncs with outbound organizational data/network traffic.
Data Transfer Size Limits
T1030
Teleport limits the data it collects and syncs with outbound organizational data/network traffic.
Exfiltration Over C2 Channel
T1048
Cyber threat actors blend exfiltrated data with network traffic to evade detection.
Cyber threat actors use the Teleport tool to exfiltrate data over a C2 protocol.
CISA and authoring organizations recommend that organizations review and implement the following detection signatures, along with: Win/malicious_confidence100% (W), Trojan:Win32/Tnega!MSR, and Trojan.Agent.Truebot.Gen, as well as YARA rules below to help detect Truebot malware.
alert tcp any any -> any any (msg:”TRUEBOT: Client HTTP Header”; sid:x; rev:1; flow:established,to_server; content:”Mozilla/112.0 (compatible|3b 20 4d 53 49 45 20 31 31 2e 30 3b 20 57 69 6e 64 6f 77 73 20 4e 54 20 31 30 2e 30 30 29|”; http_header; nocase; classtype:http-header; metadata:service http;)
CISA developed the following YARA to aid in detecting the presence of Truebot Malware.
rule CISA_10445155_01 : TRUEBOT downloader
{
meta:
Author = "CISA Code & Media Analysis"
Incident = "10445155"
Date = "2023-05-17"
Last_Modified = "20230523_1500"
Actor = "n/a"
Family = "TRUEBOT"
Capabilities = "n/a"
Malware_Type = "downloader"
Tool_Type = "n/a"
Description = "Detects TRUEBOT downloader samples"
SHA256 = "7d75244449fb5c25d8f196a43a6eb9e453652b2185392376e7d44c21bd8431e7"
strings:
$s1 = { 64 72 65 6d 6d 66 79 74 74 72 72 65 64 2e 63 6f 6d }
$s2 = { 4e 73 75 32 4f 64 69 77 6f 64 4f 73 32 }
$s3 = { 59 69 50 75 6d 79 62 6f 73 61 57 69 57 65 78 79 }
$s4 = { 72 65 70 6f 74 73 5f 65 72 72 6f 72 2e 74 78 74 }
$s5 = { 4c 6b 6a 64 73 6c 66 6a 33 32 6f 69 6a 72 66 65 77 67 77 2e 6d 70 34 }
$s6 = { 54 00 72 00 69 00 67 00 67 00 65 00 72 00 31 00 32 }
$s7 = { 54 00 55 00 72 00 66 00 57 00 65 00 73 00 54 00 69 00 66 00 73 00 66 }
condition:
5 of them
}
The following steps are recommended if organizations detect a Truebot malware infection and compromise:
CISA and the authoring organizations recommend organizations implement the below mitigations, including mandating phishing-resistant multifactor authentication (MFA) for all staff and services.
For additional best practices, see CISA’s Cross-Sector Cybersecurity Performance Goals (CPGs). The CPGs, developed by CISA and the National Institute of Standards and Technology (NIST), are a prioritized subset of IT and OT security practices that can meaningfully reduce the likelihood and impact of known cyber risks and common TTPs. Because the CPGs are a subset of best practices, CISA and co-sealers recommend software manufacturers implement a comprehensive information security program based on a recognized framework, such as the NIST Cybersecurity Framework (CSF).
Netwrix recommends using their Auditor application only on internally facing networks. System owners that don’t follow this recommendation, and use the application in externally facing instances, are at increased risk to having CVE-2022-31199 exploited on their systems.
Reduce threat of malicious actors using remote access tools by:
See the National Security Agency’s Cybersecurity Information sheet, Enforce Signed Software Execution Policies, and additional guidance below:
In addition, CISA, FBI, MS-ISAC, and CCCS recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques and to reduce the impact and risk of compromise by ransomware or data extortion actors:
In addition to applying mitigations, CISA recommends exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA recommends testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.
To get started:
CISA recommends continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.
[1] Bishop Fox: Netwrix Auditor Advisory
[2] Talos Intelligence: Breaking the Silence – Recent Truebot Activity
[3] The DFIR Report: Truebot Deploys Cobalt Strike and FlawedGrace
[4] MAR-10445155-1.v1 .CLEAR Truebot Activity Infects U.S. and Canada Based Networks
[5] Red Canary: Raspberry Robin Delivery Vector
[6] Microsoft: Raspberry Robin Worm Part of a Larger Ecosystem Pre-Ransomware Activity
[7] Telsy: FlawedGrace RAT
[8] VMware Security Blog: Carbon Black’s Truebot Detection
[9] GitHub: DFIR Report – Truebot Malware YARA Rule
Alarming Surge in TrueBot Activity Revealed with New Delivery Vectors (thehackernews.com)
Truebot Analysis Part 1
Truebot Analysis Part 2
Truebot Analysis Part 3
Truebot Exploits Netwrix Vulnerability
TrueBot malware delivery evolves, now infects businesses in the US and elsewhere
Malpedia-Silence Downloader
Printer spooling: what is it and how to fix it? | PaperCut
VMware Carbon Black and Mandiant contributed to this CSA.
The information in this report is being provided “as is” for informational purposes only. CISA and authoring agencies 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, and co-sealers.
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