MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 a4c91afb043246fd8ab645f23ada21aca414339c38ceeefddf33cc8414f26f44. While MalwareBazaar tries to identify whether the sample provided is malicious or not, there is no guarantee that a sample in MalwareBazaar is malicious.

Database Entry


Formbook


Vendor detections: 18


Intelligence 18 IOCs YARA 7 File information Comments
Download sample Add tag Delete this sample Report a False Positive

SHA256 hash: a4c91afb043246fd8ab645f23ada21aca414339c38ceeefddf33cc8414f26f44
SHA3-384 hash: 1843b5de38e7a627c46d14647b19c6d9d01a41066020f3002ee2c516244eec525e241ffce2f7f1b2c44a8552db2bdd5c
SHA1 hash: 4d59ecfe4fbb6a4a652f4c1ff6a0ec85c2996ff2
MD5 hash: 86a403b430d5ef8944a3afbbe5df6a29
humanhash: alabama-undress-wyoming-jersey
File name:INVOICE1O3UGW6.exe
Download: download sample
Signature Formbook
Create hunting rule
File size:752'136 bytes
First seen:2025-04-01 13:05:09 UTC
Last seen:Never
File type:Executable exe
MIME type:application/x-dosexec
imphash f34d5f2d4577ed6d9ceec516c1f5a744 (48'652 x AgentTesla, 19'463 x Formbook, 12'205 x SnakeKeylogger)
ssdeep 12288:njVGAMFs1hSFlsx6dPtxfyMH86VWT2xeCf82y/eAjfV4uDTF0FqYYxVFDUmTdDMk:j8AcaK2qP3fyMRs2TUeAj3DJ3rymRRl
TLSH T130F4F158726CEB03D9A66BF006B0F0B547F62DEE6521D20E4ED56CEFB876F114A00A53
TrID 71.1% (.EXE) Generic CIL Executable (.NET, Mono, etc.) (73123/4/13)
10.2% (.EXE) Win64 Executable (generic) (10522/11/4)
6.3% (.DLL) Win32 Dynamic Link Library (generic) (6578/25/2)
4.3% (.EXE) Win32 Executable (generic) (4504/4/1)
2.0% (.ICL) Windows Icons Library (generic) (2059/9)
Magika pebin
Reporter James_inthe_box
Tags:exe FormBook

Intelligence

File Origin
# of uploads :
1
# of downloads :
841
Origin country :
US US
Vendor Threat Intelligence
Malware family:
formbook
Create hunting rule
ID:
1
File name:
INVOICE1O3UGW6.exe
Verdict:
Malicious activity
Analysis date:
2025-04-01 13:08:33 UTC
Tags:
formbook stealer xloader
Link:
https://app.any.run/tasks/ac3fa102-287c-4d9f-89fe-81562757e4b2

Note:
ANY.RUN is an interactive sandbox that analyzes all user actions rather than an uploaded sample
Verdict:
Malicious
Score:
96.5%
Link:
https://cyber-fortress.com/docs/result/index.php?id=67ebe550855e5ec5240b8198
Tags:
krypt spawn msil
Result
Verdict:
Malware
Maliciousness:

Behaviour
Creating a window
Сreating synchronization primitives
Creating a process with a hidden window
Creating a file in the %AppData% directory
Enabling the 'hidden' option for recently created files
Adding an access-denied ACE
Creating a file in the %temp% directory
Launching a process
Unauthorized injection to a recently created process
Restart of the analyzed sample
Creating a file
Launching cmd.exe command interpreter
Setting browser functions hooks
Adding an exclusion to Microsoft Defender
Enabling autorun by creating a file
Unauthorized injection to a system process
Unauthorized injection to a browser process
Verdict:
Malicious
Threat level:
  10/10
Confidence:
100%
Tags:
expired-cert invalid-signature masquerade obfuscated packed packed packer_detected signed vbnet
Link:
https://www.filescan.io/uploads/67ebe48c631830704a8d36d8/reports/673dc306-988a-4a74-8304-6339c78d064a/overview
Verdict:
Malicious
Labled as:
Win/malicious_confidence_100%
Link:
https://www.hybrid-analysis.com/sample/a4c91afb043246fd8ab645f23ada21aca414339c38ceeefddf33cc8414f26f44
Result
Verdict:
UNKNOWN
Malware family:
Formbook
Create hunting rule
Verdict:
Malicious
Link:
https://analyze.intezer.com/analyses/6f85460d-56cb-4b5c-9e18-dc3d389d858f
Result
Threat name:
FormBook
Create hunting rule
Detection:
malicious
Classification:
troj.evad
Score:
100 / 100
Link:
https://www.joesandbox.com/analysis/1653709
Signature
.NET source code contains potential unpacker
Adds a directory exclusion to Windows Defender
Antivirus detection for URL or domain
C2 URLs / IPs found in malware configuration
Found direct / indirect Syscall (likely to bypass EDR)
Found malware configuration
Initial sample is a PE file and has a suspicious name
Injects a PE file into a foreign processes
Joe Sandbox ML detected suspicious sample
Loading BitLocker PowerShell Module
Malicious sample detected (through community Yara rule)
Maps a DLL or memory area into another process
Modifies the context of a thread in another process (thread injection)
Multi AV Scanner detection for dropped file
Multi AV Scanner detection for submitted file
Performs DNS queries to domains with low reputation
Queues an APC in another process (thread injection)
Sample uses process hollowing technique
Sigma detected: Powershell Base64 Encoded MpPreference Cmdlet
Sigma detected: Rundll32 Execution Without CommandLine Parameters
Sigma detected: Scheduled temp file as task from temp location
Suricata IDS alerts for network traffic
Switches to a custom stack to bypass stack traces
Tries to detect virtualization through RDTSC time measurements
Uses schtasks.exe or at.exe to add and modify task schedules
Yara detected AntiVM3
Yara detected FormBook
Behaviour
Behavior Graph:
Download SVG
behaviorgraph top1 dnsIp2 2 Behavior Graph ID: 1653709 Sample: INVOICE1O3UGW6.exe Startdate: 01/04/2025 Architecture: WINDOWS Score: 100 64 www.yselection.xyz 2->64 66 www.lphatechblog.xyz 2->66 68 10 other IPs or domains 2->68 70 Suricata IDS alerts for network traffic 2->70 72 Found malware configuration 2->72 74 Malicious sample detected (through community Yara rule) 2->74 78 11 other signatures 2->78 11 INVOICE1O3UGW6.exe 7 2->11         started        15 NAchHXQDhRvQE.exe 5 2->15         started        17 svchost.exe 2->17         started        signatures3 76 Performs DNS queries to domains with low reputation 66->76 process4 dnsIp5 54 C:\Users\user\AppData\...54AchHXQDhRvQE.exe, PE32 11->54 dropped 56 C:\...56AchHXQDhRvQE.exe:Zone.Identifier, ASCII 11->56 dropped 58 C:\Users\user\AppData\Local\...\tmp7F36.tmp, XML 11->58 dropped 60 C:\Users\user\...\INVOICE1O3UGW6.exe.log, ASCII 11->60 dropped 92 Uses schtasks.exe or at.exe to add and modify task schedules 11->92 94 Adds a directory exclusion to Windows Defender 11->94 96 Tries to detect virtualization through RDTSC time measurements 11->96 20 INVOICE1O3UGW6.exe 11->20         started        23 powershell.exe 23 11->23         started        25 powershell.exe 23 11->25         started        27 schtasks.exe 1 11->27         started        98 Multi AV Scanner detection for dropped file 15->98 100 Injects a PE file into a foreign processes 15->100 102 Switches to a custom stack to bypass stack traces 15->102 29 NAchHXQDhRvQE.exe 15->29         started        31 schtasks.exe 15->31         started        62 127.0.0.1 unknown unknown 17->62 file6 signatures7 process8 signatures9 80 Modifies the context of a thread in another process (thread injection) 20->80 82 Maps a DLL or memory area into another process 20->82 84 Sample uses process hollowing technique 20->84 86 Queues an APC in another process (thread injection) 20->86 33 explorer.exe 60 1 20->33 injected 88 Loading BitLocker PowerShell Module 23->88 35 conhost.exe 23->35         started        37 WmiPrvSE.exe 23->37         started        39 conhost.exe 25->39         started        41 conhost.exe 27->41         started        90 Found direct / indirect Syscall (likely to bypass EDR) 29->90 43 conhost.exe 31->43         started        process10 process11 45 explorer.exe 33->45         started        48 rundll32.exe 33->48         started        signatures12 104 Modifies the context of a thread in another process (thread injection) 45->104 106 Maps a DLL or memory area into another process 45->106 108 Tries to detect virtualization through RDTSC time measurements 45->108 110 Switches to a custom stack to bypass stack traces 45->110 50 cmd.exe 45->50         started        process13 process14 52 conhost.exe 50->52         started       
Score:
99%
Verdict:
Malware
File Type:
PE
Link:
https://malprob.io/report/a4c91afb043246fd8ab645f23ada21aca414339c38ceeefddf33cc8414f26f44
Detection:
formbook
Create hunting rule
Link:
https://mwdb.cert.pl/sample/a4c91afb043246fd8ab645f23ada21aca414339c38ceeefddf33cc8414f26f44/
Threat name:
ByteCode-MSIL.Backdoor.FormBook
Create hunting rule
Status:
Malicious
First seen:
2025-04-01 06:48:12 UTC
File Type:
PE (.Net Exe)
Extracted files:
18
AV detection:
26 of 38 (68.42%)
Threat level:
  5/5
Detection(s):
Suspicious file
Link:
https://check.spamhaus.org/check/?searchterm=uterv6yegjdp3cvwixzdvwrbvssbim44hdho57o7gpgiifhsn5ca._file
Result
Malware family:
formbook
Create hunting rule
Score:
  10/10
Tags:
family:formbook campaign:a03d discovery execution rat spyware stealer trojan
Link:
https://tria.ge/reports/250401-qbmj1a1qv6/
Behaviour
Modifies registry class
Scheduled Task/Job: Scheduled Task
Suspicious behavior: EnumeratesProcesses
Suspicious behavior: GetForegroundWindowSpam
Suspicious behavior: MapViewOfSection
Suspicious use of AdjustPrivilegeToken
Suspicious use of UnmapMainImage
Suspicious use of WriteProcessMemory
Enumerates physical storage devices
System Location Discovery: System Language Discovery
Suspicious use of SetThreadContext
Checks computer location settings
Command and Scripting Interpreter: PowerShell
Formbook payload
Formbook
Formbook family
Verdict:
Malicious
Tags:
n/a
YARA:
n/a
Link:
https://app.threat.zone/submission/ef20cec0-492f-4dae-9597-c87fa73e7cf1
Unpacked files
SH256 hash:
a4c91afb043246fd8ab645f23ada21aca414339c38ceeefddf33cc8414f26f44
MD5 hash:
86a403b430d5ef8944a3afbbe5df6a29
SHA1 hash:
4d59ecfe4fbb6a4a652f4c1ff6a0ec85c2996ff2
Link:
https://www.unpac.me/results/646d5db6-afce-4a33-bfbc-f22dcf3e73d1/
SH256 hash:
7a99a716be0e9224028eaaedfcc03679c7920dde20ead8a5d63766d3eca2c4dd
MD5 hash:
5b74b0a67f3829f12d19ab1266f24275
SHA1 hash:
243ca4bd21877e39c661e93c8d3c6f6e01408fbb
Detections:
SUSP_OBF_NET_ConfuserEx_Name_Pattern_Jan24
Create hunting rule
SUSP_OBF_NET_Reactor_Indicators_Jan24
Create hunting rule
Link:
https://www.unpac.me/results/646d5db6-afce-4a33-bfbc-f22dcf3e73d1/
SH256 hash:
d7b5ea2efe8f743c7a57fd8c98b778ff878d4ae864c1445de453d62046ea7143
MD5 hash:
2d1bc48a428d487d4f14ba7f3b6d5bd0
SHA1 hash:
9fc7bd58c66018ef79f3c9b38d3cb2dd1e41aa1b
Link:
https://www.unpac.me/results/646d5db6-afce-4a33-bfbc-f22dcf3e73d1/
SH256 hash:
4f59ffd1f9e8b2088120692bae2d99ddf906cab5d98435baad7ac4073ca0fe81
MD5 hash:
6782ca1720c77e90ba84e9ab5ba4f07d
SHA1 hash:
79e819dde4a4b29ca3a221f89cf73f1fd818f1de
Detections:
win_formbook_w0
Create hunting rule
win_formbook_g0
Create hunting rule
win_formbook_auto
Create hunting rule
FormBook
Create hunting rule
Windows_Trojan_Formbook
Create hunting rule
Formbook
Create hunting rule
Link:
https://www.unpac.me/results/646d5db6-afce-4a33-bfbc-f22dcf3e73d1/
Parent samples :
b225f4ef997754cc29f699ca3a8aa9aa1d39661d7c3dbc6f36a7c7a5bca235ab
92beab1ebf4cb74018b11571a5db867c2ec9d7bb0231a93a898cc3b7799558eb
acc906177a946e3e7fca9b9d962336e9e4d828297eb86761f610284f57fbf394
7a531101bc8522d52f45933945d6b8728ad7b7f3c9aaefd2d18742f8ec4000cb
bcfeb4ec31e731899a0ddd0a608aa7ecbfbdbf37f4ac3810b275ba6905a1969b
31e7559f21054aca8a1cd2287e322f22e03ac6cbc84e1265c8ac1a3367403989
4d49933551f01cc730f63fd290ecb61f4bfa880a0660f0ec7363e148ef85645a
8bd60c5add862eb634b15fad4020a9afcf8ed6f523485665c80044f90bc8b305
07abbe06a2d17f142846d33bda215df5b05355148c781cb9ff1c8f233f534cbc
f42de693aaae005ec4dcf3514621f8573b422f3a3ad1bb1af370acc7c5cba233
4ef83ac7a3bdee1a742de8de749c5afa4747acc20f8937301dcba291d1ef83d7
d0d2ac5af6ecfdf27de6c45ab86d521294350c5a64942cd15bb5d9a1ae23b0f1
205e98d299b32e102e3d6fadb9659f713601f8f713be02cec1ec0f437d3be075
6f706398207b1fd3a00de5f859dc840cf8e100175fdabe260ebb96db5980f03c
acdcfb74712f171a6527ea14112eeb4bd482b7ae74f4e2990a946c8ccea8ad65
6be92b0d491f6d5d7f65e01a3336aac1155f091ad6def08b541e07b68eda3bb4
d672848afdf3f3a32d6de454a3408acd1d9cc0c338e65461e63330e9d26128ab
05d3f3857ab465a1886005e6d6138c84b8c19447b71d1781e8169e48c371c0a3
fab2b2eddd748ae7fcbc5a1d0c2e0a7f9c75214a114d9450ca41c85ea9e71a09
1e26f69f063b034aff856a4b9bb1680824e61ebf28867a36fa30e2b3e1727526
a779cf3623ccd0238d0b5d3f01dcc911e1538a1c0a656442234b4c3335453607
c991a3ee832bc707306f68c46786afc17de14163f8d3c757516bac9953ad6f3b
582c078327541d1459228aebf38c9471b78e3a2c03cb9c375622209221970709
77295a1c2d8172b2a2eb3f5f20a2880c168dd10f01830227e4f9ae6d4a5c9a19
d37c856c37f289af0a5cf37c5e2c9ab7b115d401d945426faadc6b48234dc2ba
a4c91afb043246fd8ab645f23ada21aca414339c38ceeefddf33cc8414f26f44
94d68efe46fa5e2e5789d0a3063b48cf486e73fbfab3b84f9203372688fd1286
c21657a9253431b91837bc2089fde8e909f780b5736dd44263e54765d95dfb9d
efc8dba0e301b455b4691c60bf363ce60bc0b44921a2018ce2c1a684df8d26b9
Malware family:
FormBook
Create hunting rule
Verdict:
Malicious
Link:
https://www.vmray.com/analyses/_mb/a4c91afb0432/report/overview.html
Please note that we are no longer able to provide a coverage score for Virus Total.
Threat name:
Malicious File
Score:
1.00
Link:
https://yomi.yoroi.company/submissions/a4c91afb043246fd8ab645f23ada21aca414339c38ceeefddf33cc8414f26f44

YARA Signatures

MalwareBazaar uses YARA rules from several public and non-public repositories, such as YARAhub and Malpedia. Those are being matched against malware samples uploaded to MalwareBazaar as well as against any suspicious process dumps they may create. Please note that only results from TLP:CLEAR rules are being displayed.

Rule name:AgentTesla_DIFF_Common_Strings_01
Create hunting rule
Author:schmidtsz
Description:Identify partial Agent Tesla strings
Rule name:INDICATOR_KB_CERT_7c1118cbbadc95da3752c46e47a27438
Create hunting rule
Author:ditekSHen
Description:Detects executables signed with stolen, revoked or invalid certificates
Rule name:NET
Create hunting rule
Author:malware-lu
Rule name:PE_Digital_Certificate
Create hunting rule
Author:albertzsigovits
Rule name:pe_imphash
Create hunting rule
Rule name:Skystars_Malware_Imphash
Create hunting rule
Author:Skystars LightDefender
Description:imphash
Rule name:Sus_Obf_Enc_Spoof_Hide_PE
Create hunting rule
Author:XiAnzheng
Description:Check for Overlay, Obfuscating, Encrypting, Spoofing, Hiding, or Entropy Technique(can create FP)

File information

The table below shows additional information about this malware sample such as delivery method and external references.

Malspam

Formbook

Executable exe a4c91afb043246fd8ab645f23ada21aca414339c38ceeefddf33cc8414f26f44

(this sample)

  
Delivery method
Distributed via e-mail attachment

BLint

The following table provides more information about this file using BLint. BLint is a Binary Linter to check the security properties, and capabilities in executables.

Findings
IDTitleSeverity
CHECK_AUTHENTICODEMissing Authenticodehigh
CHECK_DLL_CHARACTERISTICSMissing dll Security Characteristics (HIGH_ENTROPY_VA)high

Comments