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Security Research

Technical Analysis of Bandit Stealer

image

Key Takeaways

  • Bandit is a new information stealer that harvests stored credentials from web browsers, FTP clients, email clients, and targets cryptocurrency wallet applications.
  • The malware sends stolen information to a command and control server via Telegram.
  • Bandit implements numerous methods to detect and evade virtual machines and malware sandboxes.
  • Bandit has been marketed and sold as a service on underground criminal forums since April 2023.
  • The malware is written using the Go programming language, which has become increasingly popular with malware developers.
     

Zscaler ThreatLabz has been tracking a new information stealer called Bandit Stealer that emerged in April 2023. Bandit collects sensitive information from victims' machines including cookies, saved login data, and credit card information from more than a dozen web browsers. The stealer also performs credential theft for popular FTP clients and email clients. Lastly, Bandit targets desktop cryptocurrency wallet applications. All of the stolen information is then exfiltrated back to a command and control (C2) server via Telegram. The malware is written in the Go (a.k.a. Golang) programming language and is especially notable with the large number of attempts to evade virtual environments and automated malware analysis platforms. 

Bandit Stealer is marketed and sold as a service in underground cybercriminal forums as shown in Figure 1. 

Figure 1: Advertisement for Bandit Stealer on an underground forum
Figure 1: Advertisement for Bandit Stealer on an underground forum

Technical Analysis

Anti-Virtual Machine & Sandbox Identification

Bandit stealer employs a number of anti-analysis techniques to thwart automated and manual analysis. The malware uses the procfs Golang library to read information about running processes and checks for the following process names shown below:

  • Xen
  • Vmware
  • VirtualBox
  • KVM
  • Sandbox
  • QEMU
  • jail

If a running process matches any of these names, Bandit will terminate execution.

The most recent Bandit samples also check for the presence of a debugger using the Windows API by calling IsDebuggerPresent and CheckRemoteDebuggerPresent. Bandit attempts to elevate permission using the runas command with the username set to Administrator as shown below:

C:\Windows\system32\runas.exe runas /user:Administrator C:\Users\saturn\Desktop\Bandit.exe

Bandit also executes the Windows Management Interface command-line (WMIC) utility to obtain the Universally Unique Identifier (UUID) of the victim machine and the screen dimensions using the following commands, respectively:

wmic csproduct get uuid

wmic desktopmonitor get screenheight, screenwidth

This information may help threat actors further identify analysis environments. In addition, Bandit uses an extensive list of IP addresses, MAC addresses, computer names, user names, process names to identify virtual environments and associate the environment with security vendors, and therefore avoid exhibiting any malicious behavior. The blacklist information is very similar to that of other prevalent open source stealers including Luna-Grabber, Kyoku-Cookie-Token-Stealer and Creal Stealer.

Bandit obtains the system’s external IP address from api.ipify.org and compares it with a list of blacklisted IP addresses shown in the Appendix. Some of these IP addresses belong to antivirus companies, which may be used to block signature updates.

Bandit stealer also retrieves the MAC address of the victim machine using the GetAdaptersAddresses Windows API and compares it with a blacklist shown in the Appendix. If there is a match, Bandit exits. Some of these MAC addresses are associated with virtualization software, so the purpose of the blacklist may be to evade malware sandboxes. Bandit Stealer also checks if the victim’s username and computer name are present in additional blacklists, which are obtained using “ cmd /c net session”.


The CreateToolhelp32Snapshot Windows API is used to capture the snapshot and traverse along the running process and matches with a list of blacklisted process names and terminates if any process is found executing in the memory shown in the Appendix.

Information Stealing Behavior

Bandit steals web browser data including saved login information, cookies, history, and credit card information stored in the browser’s user profile. Bandit targets a long list of browsers as shown in Table 1. 
 

Yandex Browser

Iridium Browser

7Star Browser

Vivaldi Browser

Google Chrome

Orbitum

Sputnik

uCozMedia

Microsoft Edge

Torch Web Browser

Kometa Browser

CentBrowser

BraveSoftware

Amigo Browser

Epic Privacy Browser

SeaMonkey browser

QupZilla

Table 1: Web browsers targeted by Bandit Stealer

The SQLite3 library is used to fetch data and the CryptUnprotectData API is used to decrypt cookies and credentials. Credit card information is also stolen, which includes the name, expiration month, year and card number.

Bandit also targets desktop cryptocurrency wallets like Electrum, Exodus, MetaMask, Guarda, Binance, Ethereum as shown in Table 2.
 

Coinbase wallet extension

Saturn Wallet extension

Binance chain wallet extension

Coin98 Wallet

TronLink Wallet

multibit Bitcoin

Terra Station

Electron Cash

Guildwallet extension

Electrum-btcp

MetaMask extension

Bither Bitcoin wallet

ronin wallet extension

multidoge coin

Kardiachain wallet extension

LiteCoin

Jaxx liberty Wallet

Dash Wallet

Math Wallet extension

Ethereum

Bitpay wallet extension

Exodus

Nifty Wallet extension

Atomic

Armory

Bytecoin Wallet

Coinomi wallet

Monero wallet

dogecoin

 

Table 2: Cryptocurrency wallets targeted by Bandit Stealer
 

Bandit also has the capability to harvest keystrokes and steal clipboard data.

Recent samples of Bandit also target credentials in the following File Transfer Protocol Client (FTP) applications shown in Table 3.

 

BlazeFTP

NovaFTP

Staff-FTP

EasyFTP

DeluxeFTP

ALFTP

GoFTP

32BitFtp

Table 3: FTP client applications targeted by Bandit
 

Bandit also targets login information for the email clients shown in Table 4.
 

MailSpring

Mailbird

Opera Mail

Pocomail

Table 4: Email client applications targeted by Bandit

Stolen data is saved in various files inside a sub-folder in the %appdata%\local directory as shown in Figure 2. The sub-folder name is based on the country code and the IP address in the format [country_code][ip_address].

Figure 2: Example information collected by Bandit Stealer
Figure 2: Example information collected by Bandit Stealer

The content of the USERINFO.txt contains a Bandit Stealer header followed by system information as shown in Figure 3.

Figure 3: Example content in the Bandit USERINFO.txt file
Figure 3: Example content in the Bandit USERINFO.txt file

Network Communication

Bandit uses the cURL utility which is installed by default since Windows 10 v1803 to transfer data using HTTP, FTP, SMTP and more. Bandit stealer abuses pastebin.com for downloading the blacklist configuration information from a hardcoded URL as shown in Figure 4.

 

Figure 4: Bandit Stealer blacklist configuration downloaded from Pastebin
Figure 4: Bandit Stealer blacklist configuration downloaded from Pastebin
 

After Bandit finishes data collection, this information is sent to the threat actor via Telegram as shown in Figure 5.

 

Figure 5: Data stolen by Bandit sent to a Telegram channel
Figure 5: Data stolen by Bandit sent to a Telegram channel
 

The Bandit threat actor has automated the parsing and extraction of the data and responds back with a JSON encoded structure as shown in Figure 6.

 

Figure 6: Example Bandit C2 response
Figure 6: Example Bandit C2 response

Conclusion

Bandit Stealer is continuously updated with new features to enhance its data collection functionality. Most recently, Bandit has added support to steal FTP and email credentials. Bandit is also capable of expanding its anti-analysis features with a dynamic configuration downloaded from Pastebin. The abuse of Telegram as a C2 server has also become an increasingly popular technique to evade network-based signatures and make takedown efforts more difficult. All of these factors set up Bandit Stealer to be a potential threat for the foreseeable future.

Zscaler Coverage

Zscaler has ensured coverage for the payloads seen in these attacks via advanced threat signatures as well as Zscaler’s advanced cloud sandbox.

 

Figure 7: The Zscaler Cloud Sandbox successfully detected the malware

Figure 7: The Zscaler Cloud Sandbox successfully detected the malware


Zscaler's multilayered cloud security platform detects indicators at various levels, as shown below:

Win64_PWS_Bandit

Indicators Of Compromise (IOCs)

 

MD5 Hash Values

Description

17c697da407acacadcaa8fb5c4885179

Bandit Stealer

fdb111c9e0c6b1a94e2bf22131e4266d

Bandit Stealer

700e57847516d1f3e4ebf02e015e9f8d

Bandit Stealer

329562ce914d3d5998ac071333e43c1c

Bandit Stealer

4ab55868b65dc8f16d9d62edfd1893fa

Bandit Stealer

34323d65b744664567c06f8c6076a6b1

Bandit Stealer

2207a896e3e2ac5dae04643e56767dcd

Bandit Stealer

caf4884072724f1d75a6288f27e8e8fe

Bandit Stealer

Appendix

IP addresses blacklisted by Bandit Stealer

88.132.231.71

95.25.204.90

34.105.72.241

193.128.114.45

78.139.8.50

34.145.89.174

109.74.154.92

95.25.81.24

20.99.160.173

109.74.154.90

213.33.142.50

92.211.52.62

88.153.199.169

109.145.173.169

109.74.154.91

88.132.227.238

84.147.62.12

34.141.146.114

93.216.75.209

35.199.6.13

194.154.78.160

212.119.227.151

192.87.28.103

80.211.0.97

92.211.109.160

195.239.51.59

88.132.226.203

34.85.253.170

195.74.76.222

192.40.57.234

195.181.175.105

23.128.248.46

188.105.91.116

64.124.12.162

88.132.225.100

35.229.69.227

34.105.183.68

34.142.74.220

92.211.192.144

34.138.96.23

92.211.55.199

188.105.91.173

34.83.46.130

192.211.110.74

79.104.209.33

109.74.154.91

188.105.91.143

35.237.47.12

178.239.165.70

34.141.245.25

34.85.243.241

87.166.50.213

34.105.0.27

34.145.195.58

193.225.193.201

34.253.248.228

35.192.93.107

195.239.51.3

84.147.54.113

212.119.227.167

 

MAC addresses blacklisted by Bandit Stealer

00:15:5d:00:07:34

00:50:56:b3:14:59

16:ef:22:04:af:76

42:01:0a:8a:00:22

00:e0:4c:b8:7a:58

ea:02:75:3c:90:9f

00:15:5d:23:4c:ad

00:1b:21:13:32:51

00:0c:29:2c:c1:21

00:e0:4c:44:76:54

1a:6c:62:60:3b:f4

a6:24:aa:ae:e6:12

00:25:90:65:39:e4

ac:1f:6b:d0:4d:e4

00:15:5d:00:00:1d

08:00:27:45:13:10

c8:9f:1d:b6:58:e4

52:54:00:3b:78:24

00:50:56:a0:cd:a8

00:1b:21:13:26:44

00:25:90:36:65:0c

00:50:56:b3:50:de

00:50:56:b3:fa:23

3c:ec:ef:43:fe:de

00:15:5d:00:00:f3

7e:05:a3:62:9c:4d

52:54:00:a0:41:92

d4:81:d7:ed:25:54

2e:b8:24:4d:f7:de

52:54:00:b3:e4:71

00:50:56:b3:f6:57

00:25:90:36:65:38

00:15:5d:13:6d:0c

90:48:9a:9d:d5:24

00:e0:4c:56:42:97

00:03:47:63:8b:de

00:50:56:a0:dd:00

00:50:56:b3:3b:a6

ca:4d:4b:ca:18:cc

00:15:5d:00:05:8d

00:15:5d:13:66:ca

92:4c:a8:23:fc:2e

f6:a5:41:31:b2:78

00:0c:29:52:52:50

56:e8:92:2e:76:0d

5a:e2:a6:a4:44:db

d6:03:e4:ab:77:8e

00:50:56:b3:42:33

ac:1f:6b:d0:48:fe

00:50:56:ae:6f:54

00:50:56:ae:b2:b0

3c:ec:ef:44:01:0c

00:e0:4c:94:1f:20

42:01:0a:96:00:33

00:50:56:b3:94:cb

06:75:91:59:3e:02

00:15:5d:00:05:d5

00:50:56:97:a1:f8

42:01:0a:8e:00:22

42:01:0a:8a:00:33

00:e0:4c:4b:4a:40

5e:86:e4:3d:0d:f6

00:50:56:b3:4c:bf

ea:f6:f1:a2:33:76

42:01:0a:8a:00:22

00:50:56:b3:ea:ee

00:50:56:b3:09:9e

ac:1f:6b:d0:4d:98

00:1b:21:13:15:20

3e:53:81:b7:01:13

00:50:56:b3:38:88

1e:6c:34:93:68:64

00:15:5d:00:06:43

00:50:56:97:ec:f2

00:50:56:a0:d0:fa

00:50:56:a0:61:aa

00:15:5d:1e:01:c8

00:e0:4c:b3:5a:2a

00:50:56:b3:91:c8

42:01:0a:96:00:22

00:50:56:b3:38:68

12:f8:87:ab:13:ec

3e:c1:fd:f1:bf:71

00:50:56:b3:21:29

60:02:92:3d:f1:69

00:50:56:a0:38:06

00:50:56:a0:6d:86

00:15:5d:00:00:b3

00:e0:4c:7b:7b:86

2e:62:e8:47:14:49

00:50:56:a0:af:75

96:2b:e9:43:96:76

00:e0:4c:46:cf:01

00:0d:3a:d2:4f:1f

00:50:56:b3:dd:03

b4:a9:5a:b1:c6:fd

42:85:07:f4:83:d0

60:02:92:66:10:79

c2:ee:af:fd:29:21

d4:81:d7:87:05:ab

56:b0:6f:ca:0a:e7

00:50:56:a0:d7:38

00:50:56:b3:ee:e1

ac:1f:6b:d0:49:86

12:1b:9e:3c:a6:2c

be:00:e5:c5:0c:e5

00:50:56:a0:84:88

52:54:00:8b:a6:08

00:15:5d:00:1c:9a

00:50:56:a0:59:10

00:1b:21:13:32:20

00:0c:29:05:d8:6e

00:15:5d:00:1a:b9

00:50:56:a0:06:8d

3c:ec:ef:44:00:d0

00:23:cd:ff:94:f0

b6:ed:9d:27:f4:fa

00:e0:4c:cb:62:08

00:50:56:ae:e5:d5

00:e0:4c:d6:86:77

00:15:5d:00:01:81

4e:81:81:8e:22:4e

00:50:56:97:f6:c8

3c:ec:ef:44:01:aa

4e:79:c0:d9:af:c3

08:00:27:3a:28:73

52:54:00:ab:de:59

00:15:5d:23:4c:a3

00:15:5d:b6:e0:cc

00:15:5d:00:00:c3

00:50:56:b3:9e:9e

00:1b:21:13:33:55

00:15:5d:00:02:26

00:50:56:a0:45:03

00:50:56:a0:39:18

00:15:5d:00:00:a4

00:50:56:b3:05:b4

12:8a:5c:2a:65:d1

32:11:4d:d0:4a:9e

00:50:56:ae:5d:ea

1c:99:57:1c:ad:e4

00:25:90:36:f0:3b

00:50:56:b3:d0:a7

94:de:80:de:1a:35

00:1b:21:13:21:26

   

 

Hardware IDs blacklisted by Bandit Stealer

7AB5C494-39F5-4941-9163-47F54D6D5016

050C3342-FADD-AEDF-EF24-C6454E1A73C9

BB233342-2E01-718F-D4A1-E7F69D026428

79AF5279-16CF-4094-9758-F88A616D81B4

03DE0294-0480-05DE-1A06-350700080009

4DC32042-E601-F329-21C1-03F27564FD6C

9921DE3A-5C1A-DF11-9078-563412000026

FF577B79-782E-0A4D-8568-B35A9B7EB76B

11111111-2222-3333-4444-555555555555

DEAEB8CE-A573-9F48-BD40-62ED6C223F20

CC5B3F62-2A04-4D2E-A46C-AA41B7050712

08C1E400-3C56-11EA-8000-3CECEF43FEDE

6F3CA5EC-BEC9-4A4D-8274-11168F640058

05790C00-3B21-11EA-8000-3CECEF4400D0

00000000-0000-0000-0000-AC1F6BD04986

6ECEAF72-3548-476C-BD8D-73134A9182C8

ADEEEE9E-EF0A-6B84-B14B-B83A54AFC548

5EBD2E42-1DB8-78A6-0EC3-031B661D5C57

C249957A-AA08-4B21-933F-9271BEC63C85

49434D53-0200-9036-2500-369025003865

4C4C4544-0050-3710-8058-CAC04F59344A

9C6D1742-046D-BC94-ED09-C36F70CC9A91

BE784D56-81F5-2C8D-9D4B-5AB56F05D86E

119602E8-92F9-BD4B-8979-DA682276D385

00000000-0000-0000-0000-AC1F6BD04972

907A2A79-7116-4CB6-9FA5-E5A58C4587CD

ACA69200-3C4C-11EA-8000-3CECEF4401AA

12204D56-28C0-AB03-51B7-44A8B7525250

00000000-0000-0000-0000-000000000000

A9C83342-4800-0578-1EE8-BA26D2A678D2

3F284CA4-8BDF-489B-A273-41B44D668F6D

921E2042-70D3-F9F1-8CBD-B398A21F89C6

5BD24D56-789F-8468-7CDC-CAA7222CC121

D7382042-00A0-A6F0-1E51-FD1BBF06CD71

BB64E044-87BA-C847-BC0A-C797D1A16A50

D8C30328-1B06-4611-8E3C-E433F4F9794E

49434D53-0200-9065-2500-65902500E439

1D4D3342-D6C4-710C-98A3-9CC6571234D5

2E6FB594-9D55-4424-8E74-CE25A25E36B0

00000000-0000-0000-0000-50E5493391EF

49434D53-0200-9036-2500-36902500F022

CE352E42-9339-8484-293A-BD50CDC639A5

42A82042-3F13-512F-5E3D-6BF4FFFD8518

00000000-0000-0000-0000-AC1F6BD04D98

777D84B3-88D1-451C-93E4-D235177420A7

60C83342-0A97-928D-7316-5F1080A78E72

38AB3342-66B0-7175-0B23-F390B3728B78

4CB82042-BA8F-1748-C941-363C391CA7F3

49434D53-0200-9036-2500-369025000C65

02AD9898-FA37-11EB-AC55-1D0C0A67EA8A

48941AE9-D52F-11DF-BBDA-503734826431

B6464A2B-92C7-4B95-A2D0-E5410081B812

B1112042-52E8-E25B-3655-6A4F54155DBF

DBCC3514-FA57-477D-9D1F-1CAF4CC92D0F

032E02B4-0499-05C3-0806-3C0700080009

FA8C2042-205D-13B0-FCB5-C5CC55577A35

00000000-0000-0000-0000-AC1F6BD048FE

FED63342-E0D6-C669-D53F-253D696D74DA

DD9C3342-FB80-9A31-EB04-5794E5AE2B4C

C6B32042-4EC3-6FDF-C725-6F63914DA7C7

EB16924B-FB6D-4FA1-8666-17B91F62FB37

2DD1B176-C043-49A4-830F-C623FFB88F3C

E08DE9AA-C704-4261-B32D-57B2A3993518

FCE23342-91F1-EAFC-BA97-5AAE4509E173

A15A930C-8251-9645-AF63-E45AD728C20C

4729AEB0-FC07-11E3-9673-CE39E79C8A00

07E42E42-F43D-3E1C-1C6B-9C7AC120F3B9

CF1BE00F-4AAF-455E-8DCD-B5B09B6BFA8F

67E595EB-54AC-4FF0-B5E3-3DA7C7B547E3

84FE3342-6C67-5FC6-5639-9B3CA3D775A1

88DC3342-12E6-7D62-B0AE-C80E578E7B07

365B4000-3B25-11EA-8000-3CECEF44010C

C7D23342-A5D4-68A1-59AC-CF40F735B363

DBC22E42-59F7-1329-D9F2-E78A2EE5BD0D

5E3E7FE0-2636-4CB7-84F5-8D2650FFEC0E

63FA3342-31C7-4E8E-8089-DAFF6CE5E967

63203342-0EB0-AA1A-4DF5-3FB37DBB0670

CEFC836C-8CB1-45A6-ADD7-209085EE2A57

96BB3342-6335-0FA8-BA29-E1BA5D8FEFBE

8DA62042-8B59-B4E3-D232-38B29A10964A

44B94D56-65AB-DC02-86A0-98143A7423BF

A7721742-BE24-8A1C-B859-D7F8251A83D3

0934E336-72E4-4E6A-B3E5-383BD8E938C3

3A9F3342-D1F2-DF37-68AE-C10F60BFB462

6608003F-ECE4-494E-B07E-1C4615D1D93C

3F3C58D1-B4F2-4019-B2A2-2A500E96AF2E

12EE3342-87A2-32DE-A390-4C2DA4D512E9

F5744000-3C78-11EA-8000-3CECEF43FEFE

D9142042-8F51-5EFF-D5F8-EE9AE3D1602A

D2DC3342-396C-6737-A8F6-0C6673C1DE08

38813342-D7D0-DFC8-C56F-7FC9DFE5C972

AF1B2042-4B90-0000-A4E4-632A1C8C7EB1

49434D53-0200-9036-2500-369025003AF0

EADD1742-4807-00A0-F92E-CCD933E9D8C1

FE455D1A-BE27-4BA4-96C8-967A6D3A9661

4D4DDC94-E06C-44F4-95FE-33A1ADA5AC27

8B4E8278-525C-7343-B825-280AEBCD3BCB

   

 

Usernames blacklisted by Bandit Stealer

WDAGUtilityAccount

server

8VizSM

Abby

BvJChRPnsxn

w0fjuOVmCcP5A

hmarc

Harry Johnson

lmVwjj9b

patex

SqgFOf3G

PqONjHVwexsS

RDhJ0CNFevzX

Lucas

3u2v9m8

kEecfMwgj

mike

Julia

Frank

PateX

HEUeRzl

8Nl0ColNQ5bq

h7dk1xPr

fred

Lisa

Louise

RGzcBUyrznReg

John

User01

PxmdUOpVyx

george

test

 

 

Computer names blacklisted by Bandit Stealer

BEE7370C-8C0C-4

WILEYPC

DESKTOP-CBGPFEE

DESKTOP-NAKFFMT

WORK

SERVER-PC

WIN-5E07COS9ALR

6C4E733F-C2D9-4

TIQIYLA9TW5M

B30F0242-1C6A-4

RALPHS-PC

DESKTOP-KALVINO

DESKTOP-VRSQLAG

DESKTOP-WG3MYJS

COMPNAME_4047

Q9IATRKPRH

DESKTOP-7XC6GEZ

DESKTOP-19OLLTD

XC64ZB

DESKTOP-5OV9S0O

DESKTOP-DE369SE

DESKTOP-D019GDM

QarZhrdBpj

EA8C2E2A-D017-4

DESKTOP-WI8CLET

ORELEEPC

AIDANPC

SERVER1

ARCHIBALDPC

LUCAS-PC

LISA-PC

JULIA-PC

MARCI-PC

JOHN-PC

d1bnJkfVlH

DESKTOP-1PYKP29

DESKTOP-B0T93D6

NETTYPC

DESKTOP-1Y2433R

DESKTOP-BUGIO

  

Process names blacklisted by Bandit Stealer

httpdebuggerui

vmwareuser

wireshark

vgauthservice

fiddler

vmacthlp

regedit

x96dbg

cmd

vmsrvc

taskmgr

x32dbg

vboxservice

vmusrvc

df5serv

prl_cc

processhacker

prl_tools

vboxtray

xenservice

vmtoolsd

qemu-ga

vmwaretray

joeboxcontrol

ida64

ksdumperclient

ollydbg

ksdumper

pestudio

joeboxserver

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