Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3d729a5f2ec48c1…

MALICIOUS

PDF

92.8 KB Created: 2021-07-22 05:01:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 19f450c51a9699df3325ec416d352cc3 SHA-1: 6d0a5dd13d3a53a2cff8d9523997155f9c5f5cd3 SHA-256: a3d729a5f2ec48c1bbe9b2b341a82c433d3a28aeb28e0bd168d17bd49fb27f4a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating it likely serves a malicious purpose. The heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to various domains, some of which are hosted on compromised CMS upload storage. The primary attack pattern appears to be leveraging these links for SEO manipulation or to distribute further malicious content, aligning with a phishing or exploit delivery strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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 http://language-coach.pl/uploads/files/44834744625.pdf In PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bff311d0ee---33918934039.pdfIn PDF document text
    • https://dcmheavyequipment.com/admin/images/file/79136712709.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/dawinenikuwijuvexakobewir.pdfIn PDF document text
    • http://denda.co.kr/ckfinder/userfiles/files/xudodatasujosiselano.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/50230341357.pdfIn PDF document text
    • http://egyptlance.com/userfiles/file/pagadifin.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/nf70nn8a7jkvcle9gknqb82g6e/bajipip.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9f212ad7a---bomodediropowelofedidox.pdfIn PDF document text
    • http://mextro.de/upload/files/16096401800.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/9d1e90c3d2513451d0f473e6636c3a00/8651373765.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a856514e0a6---95118559040.pdfIn PDF document text
    • https://jjpremiers.com/files/25815554643.pdfIn PDF document text
    • https://fizjolech.pl/userfiles/file/manupexadipeg.pdfIn PDF document text
    • https://t2sc.me/userfiles/givafilodusi.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d5bb4ef6a9---mivurafevelufison.pdfIn PDF document text
    • http://champagne-marc-chauvet.com/images/files/32421968969.pdfIn PDF document text
    • http://papinchess.ru/userfiles/file/1092656343.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16097b160d9e26---9222660751.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/349023f4ef83f373aedad088087b695d/jezofobabugomizejuxoviri.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/hcubkv19t389vumgaoojr1evlc/fepuronelebowugakasumet.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160dce7c8308d1---21001885722.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/1nm5ul91nokni9uhmb72hcl485/96262918433.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=a+large+increase+in+the+rate+of+reaction+for+a+rise+in+temperature+is+due+toPDF link annotation
    • http://irodori.kir.jp/files/file/levalo.pdfIn PDF document text
    • 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_off0001023d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1023D 11148 bytes
SHA-256: 0500be10de9855266ef377cfbed34eca4fcc638cecf202da81c4fa53382ced90
font_01_sfnt_off00011bdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BDD 17864 bytes
SHA-256: 68a15bc2c3a6dce51660f5ab92515b692bdfc0563b107b3c5153d0c8b1ba91f9
font_02_sfnt_off00014b84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14B84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1