ASEC Weekly Phishing Email Threat Trends (January 29th, 2023 – February 4th, 2023)

The ASEC analysis team monitors phishing email threats with the ASEC automatic sample analysis system (RAPIT) and honeypot. This post will cover the cases of distribution of phishing emails during the week from January 29th, 2023 to February 4th, 2023 and provide statistical information on each type. Generally, phishing is cited as an attack that leaks users’ login account credentials by disguising as or impersonating an institute, company, or individual through social engineering methods. On a broader note, the act is a technical subterfuge that enables the threat actor to perform attacks such as information leaks, malware distribution, and fraud against various targets. The focus of this post will be on the fact that phishing attacks mainly occur through emails. We will also provide a detailed classification of various attack methods that are based on phishing emails. Furthermore, we will make an effort to minimize user damage by introducing new attack types that have never been found before and emails that require users’ caution, along with their keywords. The phishing emails covered in this post will only be those that have attachments. Emails that have malicious links in the body without attachments will be excluded.

Phishing Emails

During this week, the most prevalent threat type seen in phishing email attachments was Infostealer, taking up 39%. Infostealer includes malware such as AgentTesla and FormBook, and they leak user credentials saved in web browsers, emails, and FTP clients. It was then followed by FakePage, which took up 36%. FakePages are web pages where the threat actor has imitated the screen layout, logo, and font of the real login pages or advertising pages, leading users to enter their account and password information. The input information is sent to the threat actor’s C2 server or used to induce users to access other fake websites. See <FakePage C2> below Aside from these, Downloader (9%), Exploit (4%), Trojan (4%), Worm (4%), Backdoor (2%), and Dropper (1%) types were detected.  The threat types using phishing email attachments and their order of prevalence are similar to the order of malware distribution published weekly in the <ASEC Weekly Malware Statistics>.

File Extensions in Phishing Emails

We have identified which file extensions were used by the threats above for the distribution of email attachments.  Among the phishing email attachment types, the ONE extension (4%) is notable for its continuous distribution. OneNote is a digital note-taking application developed by Microsoft, which allows users to insert content anywhere on the pages unlike word processing programs. FakePages were distributed with PDF documents or web pages scripts (HTML, SHTML, HTM) that must be executed with a web browser. Other malware, including Infostealer and downloader, came attached to emails with various file extensions including compressed files (GZ, ZIP, RAR, R00, R15, R17), disk image files (IMG), and document files (ONE, XLS, XLSX, PDF). With the exception of FakePages that are distributed through web pages script files (HTML, HTM, SHTML) and PDFs, other malware types were distributed with a variety of file extensions regardless of the threat type.

Cases of Distribution

The following are distribution cases that occurred during the week from January 29th, 2023 to February 4th, 2023. The cases will be classified into fake login pages and malware types, including Infostealer, Downloader, Exploit, and Backdoor. The numbers in email subjects and attachment filenames are unique IDs and may vary depending on the email recipient. Distribution cases with Korean subjects were also found. These are cases that specifically targeted Korean users instead of propagating themselves globally using the identical English subject and text.

Case: FakePage

Email Subject Attachment
PO ON/GLKDD 9636228 POMO9636228.htm
TAX INVOICE TAX INVOICE.shtml
Fwd: Venturx Invoices (urgenly needed) Invoice-Order#.html
ORDER.654768976 PO.654768976.html
Kookmin Bank Doc00135_xls .shtml
Comercial Invoice. PO.NO.230256789.shtml
PACKING LIST – SHIPPIING DOCUMENT Shipping Doc-2023003932.htm
PACKING LIST – SHIPPIING DOCUMENT Packing List __ Bill of Lading Copies.htm
Remittance From MP Hants Ltd to hckim Attached Remittance For hckim .shtml
Please Quote Order # 2851 with delivery. PO_.html
Order Delivery Confirmation DOC101.html
RE: UPDATED STATUS – Invoices for payment Payment Advice 1901202393820.htm
[FedEx] Arrival Notice-Original Shipment Document– P/L-B/L2327821366? Delivery Invoice.Pdf.htm
[FedEx] Arrival Notice-Original Shipment Document– P/L-B/L2327821366? Delivery Document_ KR039929203.Pdf.htm
Comercial Invoice. PO.NO.230256789.shtml
TAX RECEIPT FOR JANUARY 2023 TAX RECEIPT JAN 2023 .html
*** Kindly Download Your Files via WeTransfer! Files pdf.html
EFT Direct Deposit received on Wednesday.18.2023 EFT_Remmitance#854920_statement.htm
Important EmailEmail Subject[Korean Air] Entry Conditions and Required Quarantine Documents per Country Shipment#BL#PDF.html
gerald.zarate ACCOUNT TERMINATION Quote.pdf
Unpaid Invoice 0059012342 DUE Invoice 0059012342.one
Notificacion de recepcion de la factura Ref (906189) 01_365896d-a55z-7lkj-lamshd-36598e32mb0101.pdf
Notice! Mailbox Deactivation ***.comUser Contract Policy.htm
*******@*********.co.kr Documents Doc_____________*******@*********.co.kr.htm
Equipment, Materials and Services / HDEC Request_for_Quotation-10000257259.htm
Factura enero2023 Ref (857622) CFEG380213QM5_Factura_B_43609_BA8FE438_D923_4772_BA1_166ED8359417.pdf
Invoice #0088321 DUE Invoice88321.one
Invoice#001191 DUE Invoice#91.one
New project estimate request project SG.REV.OFFER..html
Unpaid Invoice 0059012342 DUE Invoice 0059012342.one
Remittance_Advice_***_-_Payme 766567.htm.
PO10116145444 PO10116145444.html
Anbei ist Ihre Offizielle Touristik Gewinnbenachrichtigung. MFG, Mark Kruger A Offizielle Touristik Gewinnbenachrichtigung.pdf
request for quotation Quote.pdf
Llego tu Factura Digital CFE Febrero2023 Ref (886436) TuCuentaCFE_Feb-2023-43609_BA8FE438_D923_4772_BA1.pdf
Pay adjustments report | 2023 Salary Increases message.html
Important EmailEmail Subject[Korean Air] Entry Conditions and Required Quarantine Documents per Country Shipment#BL#PDF.html
Voicemail from Zora Lexie VM274285124.html
Fwd: Envio de Factura No. F135 del 31/01/2023 CLIENT – (983831) CFEG380213QM5_Factura_B_43609_BA8FE438.pdf
RE: ยืนยันการสั่งซื้อ-INV? Order Inv.html
RE: inquiry Quote_2200001688.img
REMITTANCE ADVICE Payment advice.rar
FW: DEMANDE DE SWIFTS (SWIFT REQUEST) DEMANDE DE SWIFTS (SWIFT REQUEST),pdf.zip
Invoice#673763 Invoice #673763.iso
FW: RE: RF Quotation Doc-622.xls
RFQ-20000 TO 500000 MT/BARELLS TEST by SGS ***** ******* ********** TENDER PURCHASE.r00
Quotation Quote FCCL-1000000033.img
REQUEST FOR QUOTATION Inquiry_specification.img
confirmaci/datos_banc arios facturas y datos bancarios.pdf.img
Re[4]: very beautiful images don’t show priv_pctrs.jpg.pif
Re: very nice pictures very important best_plp.pif
FW: RE: RF Quotation Doc-623.xls
RE: 2nd Remittance // Shipping INVOICE10321.r17
Re: **TOP URGENT** Shipping Documents Shipping Doc.r15
Re: Sales contract SC-22-00005 SC-22-00005_PDF.zip
RE:BALANCE REMITTANCE TR0009.r00
DHL Express_AWB: 80258723268765 AWB 80258723268765.tar
Re[5]: very nice pics only for you wild-pctrs.pif
FW: Payment Advice Payment Copy,pdf.zip
MONEY REQUIRE TReftt1272023-pdf.gz
Unpaid Invoice 0059012342 DUE Invoice 0059012342.one
Payment Advice – Ref: [HSBC1057029141] /RFQ Priority Payment / Customer Ref: [PI10771QT90] HSBC Payment Advice_pdf.gz
PTZ| Materials & Contracts //TENDER_Mechanical Bulk Materials PTZ Materials & Contracts tender documents electronic.r00
RE: SWIFT DETAILS- TT DETAILS-BANK TRANSFER SWIFT COPY.r00
RE: Request for quote PO.zip
30 % advance order PO023010.zip
Approved Purchase Order Approved Purchase Order,pdf.rar
TR: DEMANDE DE SWIFTS (SWIFT REQUEST) DEMANDE DE SWIFTS (SWIFT REQUEST),pdf.rar
Entrega a pedido de DHL Documentos.xlsx
Shipping Documents for first order Inv Bl PL Shipping Documents for first order Inv Bl PL.zip
Re: RETURN PAYMENT TT TTRT0124013-pdf.gz
beautiful picture privateplp.exe

Case: Malware (Infostealer, Downloader, etc.)

Email Subject Attachment
Re: Inquiry Product list.zip
Re: PURCHASE ORDER ORDER00388737838.PDF.XXE
FT PHAGOCLEN (RFQ:#2020-2022 Re-Order) FT PHAGOCLEN INV#2020-2022.r00
order 27012023164648-0001.IMG
RE: PROPUESTA PEDIDO new order.doc
RE, Payment-Advice: Ref743009 Payment TT.rar
PO for Acknowledgement PO-FSSC-22-0102-R02.gz
Payment Request Payment Request-pdf.gz
SOA – NWS SHIPPING – CP WORLD MAURITIUS – REMITTANCE SLIP. 80893_payslip.docx
RE: OUTSTANDING PI// SOA PI.r17
RE: Documentacion para alta como proveedor Inv_02_02_#4.zip
RE: Request for quote PO.r00
NEW PO NEW PURCHASE ORDER #4312652902.gz
FW: Technical Clarification No: 1 TC 1 AHTSA 1093 1094 RO.pdf.gz
ENERCOV 2023 RFQ (PO 2302051) ENERCOV 2023 RFQ (PO 2302051).r01
payment 2023 Swift MT03pdf 00003747727369.r00
[FedEx] Notice on Import License New order & Specifications.xls.tgz
Payment copy payment.rar
PI مناقصه و پرداخت تایید شد Signed Tender PI & Payment Order pdf.zip
Statement for your Account under Customer ID 356-XXXXXX HSBC Account Statement 03FEB2023_pdf.gz
Cool Stuff!! HeartsOnFire.eXe
: Re: Re: Re: Re: Re: Re: Request for Proforma Invoice Purchase Order list attached.zip
AW: PO-000001306 PO-000001306.IMG
A new invoice is available (Invoice #Q0092871) Invoice #Q0092871.one
Interesting.. HeartsOnFire.eXe
Payment Details DOCUMENT-pdf.gz
FW: FEB 2023 NEW QUOTE RegScan PI-20230130.docx
Interesting.. Fun_Games.eXe
BBVA-Confirming Facturas Pagadas al Vencimiento ConfirmingPagadas.rar
RE: PO: 879204/1 FCR Draft 1 EFCR YAX1905070 E-FCR Docs_pdf.gz
PROCESSIING CONTRCT SY2-WT2103-23. PS#049847646-4094876478MBN.001
Interesting.. MyHeart4u.eXe
RE: RE: Updated SOA 210827//: Statement 210826 STATEMETNT OF ACCOUNT.rar
Cool Stuff!! Happy_XMas.eXe
AW: PO-000001306 PO-000001306.IMG
MONEY REQUIRE Purchase Order-pdf.gz
Re: Draft Docs Confirmation against PI#CK2023M1903 DRAFT DOCS INVCK2023M1903 BL PL.xls
Re: SOA Detail Payment for shipment invoices from Nov 11th – Jan 12 STATEMENT OF ACCOUNT CERIE 10134 Payment Advise.xls
By E-Mail send: Delotser Transport Operator – 0085437719 0085437719.IMG
RFQ-20000 TO 500000 MT/BARELLS TEST by SGS RFQ-20000 TO 500000 MTBARELLS TEST by SGSPDF.r00
FW: Technical Clarification No: 1 – WOR/CTC/HC-GP/2018/188 AHTSA/1093 & 1094 , 1095 – PROVISION OF ANCHOR HANDLING AND TUG SUPPLY VESSEL (AHTS) FOR PETRONAS CARIGALI SDN BHD TC 1 AHTSA 1093 1094 RO.xlsm
VSL: M/V COMMON CALYPSO, ORDER: JAN-A2623B MV COMMON CALYPSO.xls
Re:invoice and PL 26/01/2023 invoice and PL 26012023.zip
Prompt Response DoubleClick to DOWNLOAD.one
ETSO Kodu hk. ETSO_ Kodunuz40Z000004399566L..exe.xz
Re: [Reject]RV: OFERTA PO# 000938882 NSS ApplicationReject_68390(Jan31).one
PR.4828321- Request for Quotation | ATI HANDELS GmbH RFQ #4828321.doc
Hi! HeartsOnFire.eXe
Payments 2023013150028399456770010.gz
RE: Capital Tenders Group LTD PRICE REQUEST Capital Tenders Group LTD PRICE REQUEST DOC.r11
Nueva lista de pedidos y productos solicitados #Nueva lista de pedidos y productos solicitados.pdf.img
FOB Shenzhen price for its MOQ FOB Shenzhen price for its MOQ.r02
FW: Invoice & Signed Contract -NEW ORDER-038408 Invoice & Signed Contract 20230201.gz
FW: PO7574 New Order PO039445.Pdf.exe
MONEY REQUIRE ttref01312023-pdf.gz
ENEL ITALIA SpA_RFQ12345HG7$$ RFQ12345HG7Solar&Wind Procurement.r00
Paid Invoice invoice.pdf.z

The ASEC analysis team has selected keywords that users must look out for, based on the distribution cases above. If these keywords are included in the subject of the email, or if the same characteristics are found, users must exercise strict caution as they may be phishing emails from threat actors. 

Keywords to Beware of: ‘ONE

The keyword for this week is ‘ONE’, the extension of OneNote. Ever since the latest version of MS Office (Office 365) started using the policy of deactivating Office macro by default last year, there have been more and more malware strains that include the ONE extension. AsyncRAT, Qakbot, Redline, and AgentTesla are the main ones that are distributed via the ONE extension, and these malware strains have been covered in the Weekly Malware Statistics as well. As such, the team advises extra caution when executing attachments with the “ONE” extension in their emails.

FakePage C2 URL

When users enter their IDs and passwords on the login pages among the FakePages created by the threat actor, their information is sent to the attacker’s server. The list below shows the threat actor’s C2 addresses of fake login pages distributed during the week.

  • hxxps://submit-form[.]com/QgFJw0n1
  • hxxps://sagaschool.vip-saga.com[.]ua/wp-includes/zonic/newopo.php
  • hxxps://newskoodai[.]com/press/bgLf4WBIDJaAjbgLf4WBIDJaAj
  • hxxps://lifeushard[.]cyou/file.php
  • hxxps://formspree[.]io/f/xdovnyrz
  • hxxps://formspree[.]io/f/mgebolql
  • hxxps://dearasia.bambooairways[.]com/wp-admin/inke/Macus_ssw.php
  • hxxps://curriculums[.]cc/Xwery08/feedback.php
  • hxxps://bkfkr.000webhostapp[.]com/kr/kr/act.php
  • hxxp://charlesnewmarch.co[.]uk/wp-includes/4T4/mailform.php
  • hxxp://benchmarkpk[.]com/wp-includes/@/cloudlog.php
  • hxxp://accup.pluspluggg[.]com/mailb_fix.php

Attacks using phishing emails are disguised with content that can easily deceive users, such as invoices and tax payments, to induce users to access fake login pages or execute malware. Fake login pages are evolving by the second to closely resemble the original pages. The attackers pack malware in compressed file formats to escape the attachment scans of users’ security products. Users must practice strict caution and refer to recent cases of distribution to avoid being exposed to infection by malicious phishing emails. The ASEC analysis team recommends users follow the email security guidelines below.

  • Do not execute links and attachments in emails from unverified senders until they are proven to be credible.
  • Do not enter sensitive information such as login account credentials until the site is found to be reliable.
  • Do not execute attachments with unfamiliar file extensions until they are found to be reliable.
  • Use security products such as antimalware software.

According to the MITRE ATT&CK framework, phishing email attacks correspond to the following techniques.

  • Phishing for Information (Reconnaissance, ID: T1598[1])
  • Phishing (Initial Access, ID: TI1566[2])
  • Internal Spearphishing (Lateral Movement, ID: T1534[3])

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The post ASEC Weekly Phishing Email Threat Trends (January 29th, 2023 – February 4th, 2023) appeared first on ASEC BLOG.

Article Link: ASEC Weekly Phishing Email Threat Trends (January 29th, 2023 – February 4th, 2023) - ASEC BLOG