MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 f33c98f80a5d4647e5a0e5bc2a950d0aa99d0b14ed85467238b384f5e4e8f9e1. 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: 9

Maldoc score: 3

Intelligence 9 IOCs YARA 12 File information Comments

SHA256 hash:	f33c98f80a5d4647e5a0e5bc2a950d0aa99d0b14ed85467238b384f5e4e8f9e1
SHA3-384 hash:	93800670b5412c95b97464bc701571211061cd74c4ebcb3aa773c1b398bd3505bdc9cadb6dbe1aacc2873bcfb7970f74
SHA1 hash:	0a9750f71386591d6c5b19f8e595e624057f5563
MD5 hash:	89b56753e138bafa6d2406c3fed32f61
humanhash:	wolfram-one-lemon-video
File name:	document-750895311.xls
Download:	download sample
Signature	SilentBuilder Create hunting rule
File size:	91'136 bytes
First seen:	2021-02-19 10:47:26 UTC
Last seen:	2021-02-19 12:59:33 UTC
File type:	xls
MIME type:	application/vnd.ms-excel
ssdeep	1536:fEcKoSsxz1PDZLDZjlbR868O8KlVH347uDphYHceXVhca+fMHLtyeGxcl8O9pTIW:fEcKoSsxzNDZLDZjlbR868O8KlVH347/
TLSH	5E9356D5A3E5D439E718C635ABD9157D9B12EE8B0A4E03A73348B235FF742700922BC6
Reporter	abuse_ch
Tags:	SilentBuilder xls

abuse_ch

Malspam distributing SilentBuilder:

HELO: server.dns-principal-18.com
Sending IP: 162.221.187.122
From: sukiyaki-tenpura&jcom home ne jp <rex.goldner@movilidad.asegestsystem.com>
Subject: [amazon]
Attachment: charges 32.zip (contains "document-750895311.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: 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 ID	Section size	Section name
1	4096 bytes	DocumentSummaryInformation
2	4096 bytes	SummaryInformation
3	80610 bytes	Workbook

OLE vba

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

Type	Keyword	Description
AutoExec	Auto_Open	Runs when the Excel Workbook is opened
Suspicious	EXEC	May run an executable file or a system

Intelligence

File Origin

# of uploads :

# of downloads :

148

Origin country :

n/a

Vendor Threat Intelligence

Verdict:

Malicious

File type:

application/vnd.ms-excel

Has a screenshot:

False

Contains macros:

True

Detection:

n/a

Link:

https://www.capesandbox.com/analysis/117990/

Detection(s):

TwinWave.EvilDoc.QakbotTheDuck.20200928.UNOFFICIAL

TwinWave.EvilDoc.Excel4MagicPalmersArcade.20201207.UNOFFICIAL

TwinWave.EvilDoc.Excel4MacroLuresWatchingTheDectives.20210115.UNOFFICIAL

TwinWave.EvilDoc.Excel4DragoTrainingMontage.20210204.UNOFFICIAL

TwinWave.EvilDoc.EvilDoc.Excel4EnjoyTheSilence.20210212.UNOFFICIAL

TwinWave.EvilDoc.QakySoWacky.M2.20210218.UNOFFICIAL

TwinWave.EvilDoc.XLSLOLBINHammerToFall.20201218.UNOFFICIAL

Result

Verdict:

Malware

Maliciousness:

Behaviour

Creating a window

DNS request

Creating a process with a hidden window

Sending a custom TCP request by exploiting the app vulnerability

Launching a process by exploiting the app vulnerability

Result

Verdict:

Malicious

File Type:

Legacy Office File

Link:

https://app.docguard.net/f33c98f80a5d4647e5a0e5bc2a950d0aa99d0b14ed85467238b384f5e4e8f9e1/results/dashboard

Payload URLs

URL

File name

https://Z

WorkBook

Result

Verdict:

MALICIOUS

Details

Autostarting Excel Macro Sheet

Excel contains Macrosheet logic that will trigger automatically upon document open.

Result

Threat name:

Hidden Macro 4.0 IcedID

Detection:

malicious

Classification:

troj.expl.evad

Score:

100 / 100

Link:

https://www.joesandbox.com/analysis/612601

Signature

Document exploit detected (drops PE files)

Document exploit detected (process start blacklist hit)

Document exploit detected (UrlDownloadToFile)

Drops PE files to the user root directory

Found Excel 4.0 Macro with suspicious formulas

Office document tries to convince victim to disable security protection (e.g. to enable ActiveX or Macros)

Office process drops PE file

Sigma detected: Microsoft Office Product Spawning Windows Shell

System process connects to network (likely due to code injection or exploit)

Tries to detect virtualization through RDTSC time measurements

Yara detected hidden Macro 4.0 in Excel

Yara detected IcedID

Behaviour

Behavior Graph:

Download SVG

Detection:

n/a

Link:

https://mwdb.cert.pl/sample/f33c98f80a5d4647e5a0e5bc2a950d0aa99d0b14ed85467238b384f5e4e8f9e1/

Threat name:

Document-Word.Trojan.Heuristic

Status:

Malicious

First seen:

2021-02-19 10:48:09 UTC

AV detection:

3 of 47 (6.38%)

Threat level:

2/5

Detection(s):

Malicious file

Link:

https://check.spamhaus.org/check/?searchterm=6m6jr6aklvdepzna4w6cvfinbkuz2cyu5wcum4rywocplzhi7hqq._file

Result

Malware family:

n/a

Score:

10/10

Tags:

macro vmprotect xlm

Link:

https://tria.ge/reports/210219-qsgvq7vgjx/

Behaviour

Checks processor information in registry

Enumerates system info in registry

Modifies Internet Explorer settings

Suspicious behavior: AddClipboardFormatListener

Suspicious behavior: EnumeratesProcesses

Suspicious use of SetWindowsHookEx

Suspicious use of WriteProcessMemory

Loads dropped DLL

Blocklisted process makes network request

VMProtect packed file

Process spawned unexpected child process

Malware Config

Dropper Extraction:

https://shoblasaathitrust.org/ds/1902.gif

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/f33c98f80a5d4647e5a0e5bc2a950d0aa99d0b14ed85467238b384f5e4e8f9e1

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_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://www.youtube.com/watch?v=2sd7MQVofYc

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:	multiple_concats_in_excel4_formula_call Create hunting rule
Author:	Will Metcalf
Description:	Behold The Great And Powerful Match Iterator. Multiple Concats Inside of call Function
Reference:	https://blog.reversinglabs.com/blog/excel-4.0-macros

Rule name:	multiple_concats_in_excel4_formula_exec_1 Create hunting rule
Author:	Will Metcalf
Description:	Behold The Great And Powerful Match Iterator. Multiple Concats Inside of exec Function
Reference:	https://blog.reversinglabs.com/blog/excel-4.0-macros

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