MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 15c55fd5158febe95f1e54f73a9388e77b1974d6983d6fad4c7dac8961ce71bb. 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


GuLoader


Vendor detections: 11


Intelligence 11 IOCs YARA 2 File information Comments
Download sample Add tag Delete this sample Report a False Positive

SHA256 hash: 15c55fd5158febe95f1e54f73a9388e77b1974d6983d6fad4c7dac8961ce71bb
SHA3-384 hash: 8f5b4e3bccbeb2d98fad555e399151583a22344d3ef0e2a2781037fcfc66993cff30f40e9af964649fb9fe71e7cd63a6
SHA1 hash: 790d9b9d9dd45ae834139158a993721ab74ac3f4
MD5 hash: 4f56cd3f66574df8c5d4969a7a731832
humanhash: seven-ceiling-oregon-kilo
File name:Rebuffed.exe
Download: download sample
Signature GuLoader
Create hunting rule
File size:1'229'144 bytes
First seen:2023-09-21 14:51:55 UTC
Last seen:2023-09-21 15:47:30 UTC
File type:Executable exe
MIME type:application/x-dosexec
imphash 3abe302b6d9a1256e6a915429af4ffd2 (271 x GuLoader, 38 x Formbook, 25 x Loki)
ssdeep 24576:2RYkWmWEPOh5Wr++qiOKpTnDeSsp1jQW3GwiAtsp1kt4KdAZJO3FqdPH5oUPhZ:8YoW3WrtsKpTYpyW3GwY6tMqOz3
Threatray 1'616 similar samples on MalwareBazaar
TLSH T12A45335385B9EA33F3F641B3DCE60E19CEE6C7D421B92A561B017782F870AB0B41B156
TrID 47.3% (.EXE) Win32 Executable MS Visual C++ (generic) (31206/45/13)
15.9% (.EXE) Win64 Executable (generic) (10523/12/4)
9.9% (.DLL) Win32 Dynamic Link Library (generic) (6578/25/2)
7.6% (.EXE) Win16 NE executable (generic) (5038/12/1)
6.8% (.EXE) Win32 Executable (generic) (4505/5/1)
File icon (PE):PE icon
dhash icon 682e6bb3cb646c81 (4 x GuLoader, 1 x Formbook)
Reporter lowmal3
Tags:exe GuLoader signed

Code Signing Certificate

Organisation:
Issuer:
Algorithm:sha256WithRSAEncryption
Valid from:2023-05-30T07:48:00Z
Valid to:2026-05-29T07:48:00Z
Serial number: 3f769c8d4a7d9c5e9959003bc1c0608f6746a2c9
Thumbprint Algorithm:SHA256
Thumbprint: 05c5a7bd667615155e878521cb3eede4ec62534739b153eb1207772a0f1b203b
Source:This information was brought to you by ReversingLabs A1000 Malware Analysis Platform

Intelligence

File Origin
# of uploads :
2
# of downloads :
304
Origin country :
DE DE
Vendor Threat Intelligence
Detection:
n/a
Link:
https://www.capesandbox.com/analysis/450413/
Detection(s):
SecuriteInfo.com.Win32.Evo-gen.27358.21532.UNOFFICIAL
Create hunting rule

Result
Verdict:
Clean
Maliciousness:

Behaviour
Creating a window
Creating a file
Creating a file in the %temp% subdirectories
Gathering data
Verdict:
Malicious
Threat level:
  10/10
Confidence:
100%
Tags:
control lolbin overlay packed shell32
Link:
https://www.filescan.io/uploads/650c589433582f234efe933d/reports/a510c9ea-1a7c-48ec-8ffa-cc9fece61e0d/overview
Verdict:
Malicious
Labled as:
Malware
Link:
https://www.hybrid-analysis.com/sample/15c55fd5158febe95f1e54f73a9388e77b1974d6983d6fad4c7dac8961ce71bb
Result
Verdict:
MALICIOUS
Details
Windows PE Executable
Found a Windows Portable Executable (PE) binary. Depending on context, the presence of a binary is suspicious or malicious.
Verdict:
Unknown
Link:
https://analyze.intezer.com/analyses/3f990762-c8f3-46ef-9833-f90d2c2919de
Result
Threat name:
GuLoader, FormBook
Create hunting rule
Detection:
malicious
Classification:
troj.evad.spyw
Score:
100 / 100
Link:
https://www.joesandbox.com/analysis/1312399
Signature
Antivirus detection for URL or domain
Injects a PE file into a foreign processes
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 submitted file
Performs DNS queries to domains with low reputation
Queues an APC in another process (thread injection)
Sample uses process hollowing technique
Snort IDS alert for network traffic
System process connects to network (likely due to code injection or exploit)
Tries to detect Any.run
Tries to detect sandboxes and other dynamic analysis tools (process name or module or function)
Tries to harvest and steal browser information (history, passwords, etc)
Tries to steal Mail credentials (via file / registry access)
Writes to foreign memory regions
Yara detected FormBook
Yara detected GuLoader
Behaviour
Behavior Graph:
Download SVG
behaviorgraph top1 dnsIp2 2 Behavior Graph ID: 1312399 Sample: Rebuffed.exe Startdate: 21/09/2023 Architecture: WINDOWS Score: 100 34 www.dd55hh.xyz 2->34 36 www.yokaiph.store 2->36 38 20 other IPs or domains 2->38 52 Snort IDS alert for network traffic 2->52 54 Malicious sample detected (through community Yara rule) 2->54 56 Antivirus detection for URL or domain 2->56 60 3 other signatures 2->60 10 Rebuffed.exe 1 40 2->10         started        signatures3 58 Performs DNS queries to domains with low reputation 34->58 process4 file5 32 C:\Users\user\AppData\Local\...\System.dll, PE32 10->32 dropped 72 Tries to detect sandboxes and other dynamic analysis tools (process name or module or function) 10->72 74 Tries to detect Any.run 10->74 14 Rebuffed.exe 6 10->14         started        signatures6 process7 dnsIp8 46 googlehosted.l.googleusercontent.com 142.250.141.132, 443, 50000 GOOGLEUS United States 14->46 48 drive.google.com 142.251.2.113, 443, 49999 GOOGLEUS United States 14->48 76 Tries to detect Any.run 14->76 78 Maps a DLL or memory area into another process 14->78 80 Queues an APC in another process (thread injection) 14->80 18 QYHWnjdaRoXySsbUOKKs.exe 14->18 injected signatures9 process10 signatures11 50 Sample uses process hollowing technique 18->50 21 help.exe 13 18->21         started        process12 signatures13 62 Tries to steal Mail credentials (via file / registry access) 21->62 64 Tries to harvest and steal browser information (history, passwords, etc) 21->64 66 Writes to foreign memory regions 21->66 68 3 other signatures 21->68 24 explorer.exe 3 1 21->24 injected 28 firefox.exe 21->28         started        30 QYHWnjdaRoXySsbUOKKs.exe 21->30 injected process14 dnsIp15 40 www.yokaiph.store 185.27.134.59, 50024, 50025, 50026 WILDCARD-ASWildcardUKLimitedGB United Kingdom 24->40 42 cvanalysiswithai.com 67.20.76.62, 50016, 50017, 50018 UNIFIEDLAYER-AS-1US United States 24->42 44 8 other IPs or domains 24->44 70 System process connects to network (likely due to code injection or exploit) 24->70 signatures16
Detection:
n/a
Link:
https://mwdb.cert.pl/sample/15c55fd5158febe95f1e54f73a9388e77b1974d6983d6fad4c7dac8961ce71bb/
Threat name:
Win32.Trojan.Guloader
Create hunting rule
Status:
Malicious
First seen:
2023-09-21 14:29:11 UTC
File Type:
PE (Exe)
Extracted files:
13
AV detection:
19 of 34 (55.88%)
Threat level:
  5/5
Detection(s):
Suspicious file
Link:
https://check.spamhaus.org/check/?searchterm=cxcv7vivr7v6sxy6kt3tve4i455rs5gwta6w7lkmpwwisyooog5q._file
Verdict:
malicious
Label(s):
formbook
Create hunting rule
Similar samples:
0817943597641dc344c58a61071528b41db751494afc47a2e94ff39e8c6b9907
GuLoader
0ef758cdcdaa95ecd6689cf13a719dd95def885bd1c5812295c2ed65d34b735d
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1af5390c5886b3834bdc71c325178365018efb062c2922227585d14a1ae1703a
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4be39fed46206303c4a25cac7a411aab459796ad5d1c640f465d225af618f174
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6619a23606037c409d8a806d59156f73cc1493462da007f59002da7c1a9892e6
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c4dd3995cfddd9493e923bafe40de83681e9399392a3eff3ce27bedf3b8d5783
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c8a94c78a7376f91457a32319670c828f10d5616712154c969ef65bee7de122f
GuLoader
c8b9df067d8ce54ce2c376ad20bd6130dc1f3d4feac573da798e68a202b2ef6f
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dbb615f3effa4483d620bf911040f7fcf05b5c9b6f1b588e17d19c23e089e5c5
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e4a8f592359f1b3e0f6cf104c7c773ed5c249a02bfd8d770e459a074a87fd259
GuLoader
+ 1'606 additional samples on MalwareBazaar
Result
Malware family:
guloader
Create hunting rule
Score:
  10/10
Tags:
family:guloader downloader
Link:
https://tria.ge/reports/230921-r8qhlagg81/
Behaviour
Suspicious behavior: EnumeratesProcesses
Suspicious behavior: MapViewOfSection
Suspicious use of AdjustPrivilegeToken
Suspicious use of WriteProcessMemory
Enumerates physical storage devices
Suspicious use of NtCreateThreadExHideFromDebugger
Suspicious use of NtSetInformationThreadHideFromDebugger
Suspicious use of SetThreadContext
Legitimate hosting services abused for malware hosting/C2
Checks QEMU agent file
Checks computer location settings
Loads dropped DLL
Guloader,Cloudeye
Unpacked files
SH256 hash:
a0cac4cf4852895619bc7743ebeb89f9e4927ccdb9e66b1bcd92a4136d0f9c77
MD5 hash:
b0c77267f13b2f87c084fd86ef51ccfc
SHA1 hash:
f7543f9e9b4f04386dfbf33c38cbed1bf205afb3
Link:
https://www.unpac.me/results/52026a50-bd59-44d6-b4f6-5dbeda185cf6/
SH256 hash:
15c55fd5158febe95f1e54f73a9388e77b1974d6983d6fad4c7dac8961ce71bb
MD5 hash:
4f56cd3f66574df8c5d4969a7a731832
SHA1 hash:
790d9b9d9dd45ae834139158a993721ab74ac3f4
Link:
https://www.unpac.me/results/52026a50-bd59-44d6-b4f6-5dbeda185cf6/
Malware family:
GuLoader
Create hunting rule
Verdict:
Malicious
Link:
https://www.vmray.com/analyses/_mb/15c55fd5158f/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/15c55fd5158febe95f1e54f73a9388e77b1974d6983d6fad4c7dac8961ce71bb

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:Ins_NSIS_Buer_Nov_2020_1
Create hunting rule
Author:Arkbird_SOLG
Description:Detect NSIS installer used for Buer loader
Rule name:PE_Digital_Certificate
Create hunting rule
Author:albertzsigovits

File information

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

Malspam

GuLoader

Executable exe 15c55fd5158febe95f1e54f73a9388e77b1974d6983d6fad4c7dac8961ce71bb

(this sample)

  
Delivery method
Distributed via e-mail attachment
Cape
Cape
https://www.capesandbox.com/analysis/450413/

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