Malicious PDF — malware analysis report

Static analysis result for SHA-256 a351b533e5bd61fc…

MALICIOUS

PDF

79.6 KB Created: 2021-09-03 19:10:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 0556534a44f2b79bcc5478fe3d0d5218 SHA-1: 8f6c707a0026ca7b9e7cf0fc49457f1b110f11d5 SHA-256: a351b533e5bd61fcc0a99013774e3e92027a1a6edcbe8c050342cf039e7fe5ca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution attempt. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and disposable hosting, likely to redirect users to malicious content. The PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/161234f6f83f11---77872511449.pdf In PDF document text
    • http://nova-auto.com/upload/62243034110.pdfIn PDF document text
    • https://soportedevida.mx/ckfinder/userfiles/files/94995900053.pdfIn PDF document text
    • http://capesociety.ca/uploads/files/tozip.pdfIn PDF document text
    • http://csc0311.com/userfiles/file/20210607194217_403mhe.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba5cc4a0503---2036707127.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/81572073756.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160cb64c461024---82022329816.pdfIn PDF document text
    • http://www.bc-arman.kz/ckfinder/userfiles/files/57314731152.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609c9abe1f232---78877146944.pdfIn PDF document text
    • http://cungcapbaoduongcuanhatban.com/upload/files/xopowofolosuterifemomafab.pdfIn PDF document text
    • http://hjtech.org/admin/upfile/file/pepemi.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/d115e345d31ccb3fc4c6f40d81cba50c/64548494991.pdfIn PDF document text
    • http://g-shocktou.com/user_file/file/53712067515.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1607b626840f59---fodofurerakekegojafo.pdfIn PDF document text
    • http://www.tekkoo.net/images/library/File/88956265684.pdfIn PDF document text
    • https://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/c1844d5c2bac490c0a9e0c097a9ad10f/kaninivanuluzapogimodi.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/0eaquthfnrl4pta6vobslfhpm2/nupovubakix.pdfIn PDF document text
    • http://dlevitin.ru/fck_editor_files/files/44156215662.pdfIn PDF document text
    • http://cdkkck.com/uploadfile/file/20210627225626.pdfIn PDF document text
    • http://studioindelicato.com/userfiles/files/16317512318.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/161082197251a5---gexonugizem.pdfIn PDF document text
    • http://energo-winstal.pl/userfiles/file/10675272461.pdfIn PDF document text
    • http://cyc.cz/pictures/clanky/files/10765801198.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16115da0509034---12718395307.pdfIn PDF document text
    • http://mega-stainlesssteel.com/uploads/image/files/suwalisukemipulila.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=campylobacter+jejuni+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d0fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0FE 17932 bytes
SHA-256: c76787c2c9d0e72aff36bbee5fc68b7bd7f2e599b64f4e6e0a39e630f8d31217
font_01_sfnt_off0000ff34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001174b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1174B 11128 bytes
SHA-256: 3808384915843fe64fa55286563bcffd2640a9fc9c2fba7355b98d5ae0aac3a0