Malicious PDF — malware analysis report

Static analysis result for SHA-256 13ade4912afd1100…

MALICIOUS

PDF

86.8 KB Created: 2021-07-21 08:04:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 965caeb3e3360e9c14d7ff902f92ef6f SHA-1: 4010219d6833819896bfc86cfcdee1b6716d9c87 SHA-256: 13ade4912afd1100e0bfa2d048f2ffc847ee4936f097eb8b15e32e75994ffc23
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous websites, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO spam or to distribute further payloads. The document body is heavily obfuscated and does not provide clear instructions, but the overall structure and heuristic firings suggest a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9730

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://hkbca.org/UploadFiles/file/20210524030742130.pdf In PDF document text
    • https://lamaisonducoeur.ca/upload/editor/file/93487163084.pdfIn PDF document text
    • http://palenice.net/obrazky_clanky/file/doditoleke.pdfIn PDF document text
    • https://clubelsendero.com/img_pag/file/ridadujepisiras.pdfIn PDF document text
    • https://roeveragri.ac.in/wp-content/plugins/super-forms/uploads/php/files/efc2d06f3433aa82026bdcf632e7a445/51824374123.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/58366de422bbf2e8a111c32734675bc3/60868160013.pdfIn PDF document text
    • http://myexamadvisor.com/fck_uploads/files/78718513640.pdfIn PDF document text
    • http://mspchicagolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/35495156796.pdfIn PDF document text
    • http://polesprogettazioni.com/userfiles/files/loladuxoba.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/88799862358.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/q4tag05hu11hm048tr38fpqlr4/69693250567.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16098b7695a50e---47948004377.pdfIn PDF document text
    • http://loveperfectionschool.com/upload/file/joxexi.pdfIn PDF document text
    • http://muzeumostrowiec.pl/obrazy/file/79678184403.pdfIn PDF document text
    • http://bertoniamministrazione.it/bertoni/public/file/43419897316.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/c2f3a6f8a4650c6cec98584c2d35921f/dulakutemizidanu.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16074cfd3b0038---libiwelanugefabanow.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/71444fc3586d3478699fb1e6563c12e5/30825117229.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/a78ad1b97f6a997a9b2eb56364c16001/32731431969.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/f434440b175abe63cb6569e05408491b/49273198182.pdfIn PDF document text
    • http://castanienfamily.com/clients/74558/File/wawokupifipul.pdfIn PDF document text
    • https://abugfreemind.com/userfiles/file/30474163406.pdfIn PDF document text
    • http://fritz-fahrlaender.ch/download/woridatixelajugiduder.pdfIn PDF document text
    • http://nenorm.com/files/files/setesevazurogoletafa.pdfIn PDF document text
    • http://stylekd.ru/files/vejiwugepinexuzokowefuv.pdfIn PDF document text
    • https://agatanorek.com/files/file/vuwuvetexunaruvidasunaf.pdfIn PDF document text
    • http://cosmic-kino.ru/sadm_files/dulirixojisopisuligek.pdfIn PDF document text
    • https://alibabaoman.com/basefile/alibabaomancom/files/pudewaxorewafok.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=travel+trailer+furnace+troubleshootingPDF 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_off0000f1eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1EB 10884 bytes
SHA-256: c6a193f5eb3161ba18fc9c614f624ccd6ee99c9dded80b1edcac084c906d384c
font_01_sfnt_off00010b0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B0B 16360 bytes
SHA-256: eaada359fbc1d465e5740d42b97fc7cba5b23285506db04417b24dbe230dd009
font_02_sfnt_off00013574.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13574 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1