MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 bcc1731e3f2dc4772be5ad445247f717b82ec84eda5f86adc57824241dc77823. 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: 7


Intelligence 6 IOCs YARA 9 File information Comments
Download sample Add tag Delete this sample Report a False Positive

SHA256 hash: bcc1731e3f2dc4772be5ad445247f717b82ec84eda5f86adc57824241dc77823
SHA3-384 hash: 73a6b534863679604f964abe4c92513964c3a81a7c7eba4ff21a6824efbbcadc4041e7dbda676d1677df1bca06e8a357
SHA1 hash: 1bbc9138c1f5fbd83c0484b2e00fc7d0ec03bb4d
MD5 hash: e1bddad335af1cbf14788dfd3b898a59
humanhash: pluto-spring-sad-eighteen
File name:Complaint-Letter_1492841762_12042020.xls
Download: download sample
Signature SilentBuilder
Create hunting rule
File size:44'032 bytes
First seen:2020-12-04 16:10:11 UTC
Last seen:2020-12-04 18:05:56 UTC
File type:Excel file xls
MIME type:application/vnd.ms-excel
ssdeep 768:gUcKoSsxz1PDZLDZjlbR868O8KldzH3x17uDphYHceXVhca+fMHLtyeGxcbB8OUE:gUcKoSsxz1PDZLDZjlbR868O8KlVH3fD
TLSH 6913E7AEF659CC09E819033A50A34AAA3367FC888FA7478B365CF7065FB52C04B13517
Reporter ffforward
Tags:Qakbot qbot Quakbot SilentBuilder xls

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: 7
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
333891 bytesWorkbook
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
SuspiciousEXECMay run an executable file or a system
SuspiciousHex StringsHex-encoded strings were detected, may be used to obfuscate strings (option --decode to see all)
SuspiciousBase64 StringsBase64-encoded strings were detected, may be used to obfuscate strings (option --decode to see all)

Intelligence

File Origin
# of uploads :
2
# of downloads :
400
Origin country :
n/a
Vendor Threat Intelligence
Detection(s):
TwinWave.EvilDoc.DOCXSTRGOOD.AOEX4.BITSNEEDEDFOR.DLLREGISTERSERVER.200327.UNOFFICIAL
Create hunting rule

TwinWave.EvilDoc.DOCXSTRGOOD.AOEX4.BITSNEEDEDFOR.DLLREGISTERSERVER.200416.UNOFFICIAL
Create hunting rule

TwinWave.EvilDoc.Excel4Macro.HiddenSheetDLWAKEUP.20200310.UNOFFICIAL
Create hunting rule

TwinWave.EvilDoc.HiddenSheetExcel4LureRecognizer.20200915.UNOFFICIAL
Create hunting rule

TwinWave.EvilDoc.QakbotTheDuck.20200928.UNOFFICIAL
Create hunting rule

Result
Verdict:
Malware
Maliciousness:

Behaviour
Creating a window
Creating a file in the %temp% directory
Launching the default Windows debugger (dwwin.exe)
Launching a process by exploiting the app vulnerability
Result
Verdict:
Malicious
File Type:
Legacy Office File
Link:
https://app.docguard.net/bcc1731e3f2dc4772be5ad445247f717b82ec84eda5f86adc57824241dc77823/results/dashboard
Document image
Image:
Download PNG
Document image
Result
Verdict:
UNKNOWN
Details
Autostarting Excel Macro Sheet
Excel contains Macrosheet logic that will trigger automatically upon document open.
Document With Minimal Content
Document contains less than 1 kilobyte of semantic information.
Detection:
n/a
Link:
https://mwdb.cert.pl/sample/bcc1731e3f2dc4772be5ad445247f717b82ec84eda5f86adc57824241dc77823/
Threat name:
Document-Word.Backdoor.Quakbot
Create hunting rule
Status:
Malicious
First seen:
2020-12-04 16:11:06 UTC
AV detection:
10 of 29 (34.48%)
Threat level:
  5/5
Detection(s):
Suspicious file
Link:
https://check.spamhaus.org/check/?searchterm=xtaxghr7fxchok7fvvcfer7xc64c5sco3jpynlofpascihohparq._file
Result
Malware family:
n/a
Score:
  10/10
Tags:
macro
Link:
https://tria.ge/reports/201204-6bwtzpe5dj/
Behaviour
Enumerates system info in registry
Modifies Internet Explorer settings
Suspicious behavior: AddClipboardFormatListener
Suspicious use of SetWindowsHookEx
Suspicious use of WriteProcessMemory
Checks processor information in registry
Suspicious behavior: EnumeratesProcesses
Suspicious use of FindShellTrayWindow
Process spawned suspicious child process
Process spawned unexpected child process
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/bcc1731e3f2dc4772be5ad445247f717b82ec84eda5f86adc57824241dc77823

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:Excel_Hidden_Macro_Sheet
Create hunting rule
Rule name:IPPort_combo_mem
Create hunting rule
Author:James_inthe_box
Description:IP and port combo
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: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:SUSP_Excel4Macro_AutoOpen
Create hunting rule
Author:John Lambert @JohnLaTwC
Description:Detects Excel4 macro use with auto open / close
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.

Malspam

SilentBuilder

Excel file xls bcc1731e3f2dc4772be5ad445247f717b82ec84eda5f86adc57824241dc77823

(this sample)

  
Link
https://tria.ge/201204-6h2bnpww5a
  
Delivery method
Distributed via e-mail attachment

Comments