MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 4e380065d1bf7c83b5d986c190cf8886046cf91e7408573d67fe01203efec1a2. 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: 8

Maldoc score: 13

Intelligence 8 IOCs YARA 7 File information Comments

SHA256 hash:	4e380065d1bf7c83b5d986c190cf8886046cf91e7408573d67fe01203efec1a2
SHA3-384 hash:	c100a4b813e28e030953beb25f46b095888e76374e00e9a995122f61fa5e14098d3e0c74d92a933948d6425f3f22bec1
SHA1 hash:	2ae5038cc6cb4cfceb3dae07e3b4400b6bfef441
MD5 hash:	07be2bbb25c6af7c0ee124dd823196e6
humanhash:	mango-lion-network-bulldog
File name:	document-891775316.xls
Download:	download sample
Signature	SilentBuilder Create hunting rule
File size:	332'800 bytes
First seen:	2020-12-18 17:00:51 UTC
Last seen:	2020-12-18 18:33:56 UTC
File type:	xls
MIME type:	application/vnd.ms-excel
ssdeep	6144:acKoSsxzNDZLDZjlbR868O8KlVH30bcq7uDphYHceXVhca+fMHLty/xcl8OUM+NF:pirWYRHkwCGkTSH8pI6
TLSH	3E64F1C6774ACAC5E915433408C7C6F72B2BFC419F7507C7BA85B31EAE365908AD2682
Reporter	abuse_ch
Tags:	SilentBuilder xls

abuse_ch

Malspam distributing SilentBuilder:

HELO: smtp01.emerald.cmh.synacor.com
Sending IP: 208.47.184.7
From: jmbuzzard@wavecable.com
Subject: RE: PIANO DI RIENTRO PRATICA CO4042791 TRUCCO FEDERICA
Attachment: contract_2815_2_claim-11.zip (contains "document-891775316.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: 13

Application name is Microsoft Excel

Office document is in OLE format

Office document contains VBA Macros

OLE dump

MalwareBazaar was able to identify 18 sections in this file using oledump:

Section ID	Section size	Section name
1	102 bytes	CompObj
2	284 bytes	DocumentSummaryInformation
3	200 bytes	SummaryInformation
4	309487 bytes	Workbook
5	573 bytes	_VBA_PROJECT_CUR/PROJECT
6	71 bytes	_VBA_PROJECT_CUR/PROJECTwm
7	3564 bytes	_VBA_PROJECT_CUR/VBA/Tenr
8	2949 bytes	_VBA_PROJECT_CUR/VBA/_VBA_PROJECT
9	1638 bytes	_VBA_PROJECT_CUR/VBA/__SRP_0
10	228 bytes	_VBA_PROJECT_CUR/VBA/__SRP_1
11	816 bytes	_VBA_PROJECT_CUR/VBA/__SRP_2
12	190 bytes	_VBA_PROJECT_CUR/VBA/__SRP_3
13	248 bytes	_VBA_PROJECT_CUR/VBA/__SRP_4
14	66 bytes	_VBA_PROJECT_CUR/VBA/__SRP_5
15	539 bytes	_VBA_PROJECT_CUR/VBA/dir
16	1149 bytes	_VBA_PROJECT_CUR/VBA/1
17	984 bytes	_VBA_PROJECT_CUR/VBA/2
18	984 bytes	_VBA_PROJECT_CUR/VBA/3

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	RUN	May run an executable file or a system command
Suspicious	Lib	May run code from a DLL
Suspicious	URLDownloadToFileA	May download files from the Internet
Suspicious	EXEC	May run an executable file or a system
Suspicious	Hex Strings	Hex-encoded strings were detected, may be used to obfuscate strings (option --decode to see all)
Suspicious	Base64 Strings	Base64-encoded strings were detected, may be used to obfuscate strings (option --decode to see all)

Intelligence

File Origin

# of uploads :

# of downloads :

308

Origin country :

n/a

Vendor Threat Intelligence

Verdict:

File type:

application/vnd.ms-excel

Has a screenshot:

False

Contains macros:

False

Detection(s):

TwinWave.EvilDoc.DOCXSTRGOOD.AOEX4.BITSNEEDEDFOR.URLDOWNLOADTOFILE.200327.UNOFFICIAL

TwinWave.EvilDoc.DOCXSTRGOOD.AOEX4.BITSNEEDEDFOR.DLLREGISTERSERVER.200327.UNOFFICIAL

TwinWave.EvilDoc.DOCXSTRGOOD.AOEX4.BITSNEEDEDFOR.URLDOWNLOADTOFILE.200415.UNOFFICIAL

TwinWave.EvilDoc.DOCXSTRGOOD.AOEX4.BITSNEEDEDFOR.DLLREGISTERSERVER.200416.UNOFFICIAL

TwinWave.EvilDoc.Excel4MagicPalmersArcade.20201207.UNOFFICIAL

Result

Verdict:

Malware

Maliciousness:

Behaviour

Creating a window

DNS request

Creating a file

Creating a process with a hidden window

Launching a process

Sending an HTTP GET request

Unauthorized injection to a system process

Launching a process by exploiting the app vulnerability

Enabling autorun by creating a file

Result

Verdict:

Malicious

File Type:

Legacy Excel File with Macro

Link:

https://app.docguard.net/4e380065d1bf7c83b5d986c190cf8886046cf91e7408573d67fe01203efec1a2/results/dashboard

Result

Verdict:

MALICIOUS

Details

Macro Contains Suspicious String

Detected a macro with a suspicious string. Suspicious strings include privileged function calls, obfuscations, odd registry keys, etc...

Macro with DLL Reference

Detected macro logic that will load additional functionality from Dynamically Linked Libraries (DLLs). While not explicitly malicious, this is a common tactic for accessing APIs that are not otherwised exposed via Visual Basic for Applications (VBA).

Autostarting Excel Macro Sheet

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

Result

Threat name:

Hidden Macro 4.0

Detection:

malicious

Classification:

expl.evad

Score:

100 / 100

Link:

https://www.joesandbox.com/analysis/566531

Signature

Allocates memory in foreign processes

Antivirus detection for URL or domain

Document contains an embedded VBA macro with suspicious strings

Document exploit detected (drops PE files)

Document exploit detected (process start blacklist hit)

Document exploit detected (UrlDownloadToFile)

Downloads files with wrong headers with respect to MIME Content-Type

Drops PE files to the user root directory

Found Excel 4.0 Macro with suspicious formulas

Injects code into the Windows Explorer (explorer.exe)

Machine Learning detection for dropped file

Maps a DLL or memory area into another process

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

Office process drops PE file

Opens the same file many times (likely Sandbox evasion)

Overwrites code with unconditional jumps - possibly settings hooks in foreign process

Sigma detected: Microsoft Office Product Spawning Windows Shell

Uses schtasks.exe or at.exe to add and modify task schedules

Writes to foreign memory regions

Behaviour

Behavior Graph:

Download SVG

Detection:

n/a

Link:

https://mwdb.cert.pl/sample/4e380065d1bf7c83b5d986c190cf8886046cf91e7408573d67fe01203efec1a2/

Threat name:

Document-Word.Trojan.Valyria

Status:

Malicious

First seen:

2020-12-18 17:01:06 UTC

AV detection:

13 of 29 (44.83%)

Threat level:

5/5

Detection(s):

Malicious file

Link:

https://check.spamhaus.org/check/?searchterm=jy4aazorx56ihnozq3azbt4iqycgz6i6oqefoplh7yasapx6ygra._file

Result

Malware family:

n/a

Score:

10/10

Tags:

macro

Link:

https://tria.ge/reports/201218-bsrzxn8w82/

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

Office loads VBA resources, possible macro or embedded object present

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/4e380065d1bf7c83b5d986c190cf8886046cf91e7408573d67fe01203efec1a2

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:	IPPort_combo_mem Create hunting rule
Author:	James_inthe_box
Description:	IP and port combo

Rule name:	QakBot Create hunting rule
Author:	kevoreilly
Description:	QakBot Payload

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_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

zip 76b9a531e2e41474dae479ca56e9611376cf3eced4e2d2ac78ee973eaed33a51

SilentBuilder

xls 4e380065d1bf7c83b5d986c190cf8886046cf91e7408573d67fe01203efec1a2

(this sample)

Dropped by

MD5 b37a22ae636d0f5c8463c17162b97b72

Delivery method

Distributed via e-mail attachment

Dropped by

SHA256 76b9a531e2e41474dae479ca56e9611376cf3eced4e2d2ac78ee973eaed33a51

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