MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 f82a3b15901da167017395e4158995302d01abbb9b7f259465eca8f66f42fb5c. 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


SilentBuilder


Vendor detections: 6


Maldoc score: 3


Intelligence 6 IOCs YARA 11 File information Comments
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SHA256 hash: f82a3b15901da167017395e4158995302d01abbb9b7f259465eca8f66f42fb5c
SHA3-384 hash: 2690baf27695946ec43548bf0ab419723be611ae36c925b5cabe84d6f20f6b34566d91d64bde425db48e96eed14b612a
SHA1 hash: c9d47b8cf3debfe3f714c6eb497829a8ad2bd1fc
MD5 hash: 88da57baad066838d62daa0d17658eb0
humanhash: quiet-edward-jersey-high
File name:88da57ba_by_Libranalysis
Download: download sample
Signature SilentBuilder
Create hunting rule
File size:300'032 bytes
First seen:2021-05-03 17:04:42 UTC
Last seen:2021-05-03 17:44:43 UTC
File type:Excel file xlsx
MIME type:application/vnd.ms-excel
ssdeep 6144:KcPiTQAVW/89BQnmlcGvgZ7r3J8b5IPJK++3eO:uqO
TLSH E554C482A1139D65E1549F35D865412C4EABEEA97B38F2872C04FFB7FB330E02E41959
Reporter Libranalysis
Tags:SilentBuilder


Avatar
Libranalysis
Uploaded as part of the sample sharing project

Office OLE Information

This malware samples appears to be an Office document. The following table provides more information about this document using oletools and oledump.

OLE id
Maldoc score: 3
Application name is Microsoft Excel
Office document is in OLE format
OLE dump

MalwareBazaar was able to identify 3 sections in this file using oledump:

Section IDSection sizeSection name
14096 bytesDocumentSummaryInformation
24096 bytesSummaryInformation
3288088 bytesBook
OLE vba

MalwareBazaar was able to extract and deobfuscate VBA script(s) the following information from OLE objects embedded in this file using olevba:

TypeKeywordDescription
AutoExecAuto_OpenRuns when the Excel Workbook is opened
Hex StringTTdVTeFP5454645654654650
SuspiciousHex StringsHex-encoded strings were detected, may be used to obfuscate strings (option --decode to see all)

Intelligence

File Origin
# of uploads :
2
# of downloads :
94
Origin country :
n/a
Vendor Threat Intelligence
Verdict:
Legit
File type:
application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Has a screenshot:
False
Contains macros:
True
Detection(s):
TwinWave.EvilDoc.Excel4DragoTrainingMontage.20210204.UNOFFICIAL
Create hunting rule

TwinWave.EvilDoc.QakySoWacky.M2.20210218.UNOFFICIAL
Create hunting rule

TwinWave.EvilDoc.QakySoWacky.M3.20210301.UNOFFICIAL
Create hunting rule

TwinWave.EvilDoc.XL4MQakyEsqHomeComing.20210423.UNOFFICIAL
Create hunting rule

Result
Verdict:
Malicious
File Type:
Legacy Office File
Link:
https://app.docguard.net/f82a3b15901da167017395e4158995302d01abbb9b7f259465eca8f66f42fb5c/results/dashboard
Payload URLs
URL
File name
otusmail.com/b/vegas.
Book
Document image
Image:
Download PNG
Document image
Result
Verdict:
MALICIOUS
Link:
https://labs.inquest.net/dfi/sha256/f82a3b15901da167017395e4158995302d01abbb9b7f259465eca8f66f42fb5c
Detection:
n/a
Link:
https://mwdb.cert.pl/sample/f82a3b15901da167017395e4158995302d01abbb9b7f259465eca8f66f42fb5c/
Detection(s):
Suspicious file
Link:
https://check.spamhaus.org/check/?searchterm=7avdwfmqdwqwoaltsxsblcmvgawqdk53tn7slfdf5supm32c7noa._file
Result
Malware family:
bazarbackdoor
Create hunting rule
Score:
  10/10
Tags:
family:bazarbackdoor backdoor macro xlm
Link:
https://tria.ge/reports/210503-dw1yzwkea6/
Behaviour
Checks processor information in registry
Enumerates system info in registry
Modifies Internet Explorer settings
Suspicious behavior: AddClipboardFormatListener
Suspicious use of SetWindowsHookEx
Suspicious use of WriteProcessMemory
Suspicious use of SetThreadContext
Loads dropped DLL
Blocklisted process makes network request
Downloads MZ/PE file
BazarBackdoor
Process spawned unexpected child process
Malware Config
Dropper Extraction:
https://otusmail.com/b/vegas.dll
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/f82a3b15901da167017395e4158995302d01abbb9b7f259465eca8f66f42fb5c

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:Email_stealer_bin_mem
Create hunting rule
Author:James_inthe_box
Description:Email in files like avemaria
Rule name:INDICATOR_DOC_PhishingPatterns
Create hunting rule
Author:ditekSHen
Description:Detects OLE, RTF, PDF and OOXML (decompressed) documents with common phishing strings
Rule name:IPPort_combo_mem
Create hunting rule
Author:James_inthe_box
Description:IP and port combo
Rule name:multiple_concats_in_excel4_exec_enjoy_the_silence
Create hunting rule
Author:Will Metcalf
Description:Behold The Great And Powerful Match Iterator. Multiple Concats with register Function SILENT BUILDER EDITION
Reference:https://blog.reversinglabs.com/blog/excel-4.0-macros
Rule name:Ping_Del_method_bin_mem
Create hunting rule
Author:James_inthe_box
Description:cmd ping IP nul del
Rule name:Select_from_enumeration
Create hunting rule
Author:James_inthe_box
Description:IP and port combo
Rule name:SharedStrings
Create hunting rule
Author:Katie Kleemola
Description:Internal names found in LURK0/CCTV0 samples
Rule name:silentbuilder_03_11
Create hunting rule
Author:James Quinn
Description:SilentBuilder xls sheets
Rule name:silentbuilder_03_17
Create hunting rule
Author:James Quinn
Description:SilentBuilder xls sheets
Rule name:SUSP_EnableContent_String_Gen
Create hunting rule
Author:Florian Roth
Description:Detects suspicious string that asks to enable active content in Office Doc
Reference:Internal Research
Rule name:UAC_bypass_bin_mem
Create hunting rule
Author:James_inthe_box
Description:UAC bypass in files like avemaria

File information

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

Comments