Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc6b0ad0ca0eaf02…

MALICIOUS

PDF

82.8 KB Created: 2021-09-08 06:28:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f278c276967a92eeaf4af191ea9f5727 SHA-1: cb3491d6cb134733a7205b731ef89124e3172701 SHA-256: dc6b0ad0ca0eaf02f389394a1f6377c0bab4025743ff7cb1828e3adf3d76e9f8
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to other PDF files, many hosted on compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO abuse. The presence of multiple external URIs and link farm heuristics suggests an attempt to distribute or obscure malicious content through a network of compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://hondaotohaiphong.vn/upload/files/mojifinawusotudijexefow.pdf In PDF document text
    • http://paraglider24.de/pics/fotos/1/file/89670236514.pdfIn PDF document text
    • http://brainbond.ro/userfiles/file/9111235147.pdfIn PDF document text
    • https://shriayurvednagpur.org/public/ckfinder/userfiles/files/vusitirosajomopukuwob.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/11390590845.pdfIn PDF document text
    • http://bociany.sk/media/file/26624451445.pdfIn PDF document text
    • https://ikincielinmak.com/upload/ckfinder/files/pexekil.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/68131318308.pdfIn PDF document text
    • https://bio86.net/fichiers/96672441806.pdfIn PDF document text
    • http://bpsstudio.hu/uploads/13863654756.pdfIn PDF document text
    • https://www.helmmsp.ca/wp-content/plugins/super-forms/uploads/php/files/8c94b8ff47d950ad046da17f56579d3d/figeledejuzadama.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/748061c51337d9aa424bcc1bf7049f17/febefaranabiveruzoxa.pdfIn PDF document text
    • http://bet-balance.com/userfiles/file/69796400538.pdfIn PDF document text
    • http://xn--80adic7alej3d.xn--p1ai/userfiles/file/42252999543.pdfIn PDF document text
    • http://boxerdapolenta.com/cmsimple/images/file/lamerufegabivewaxafalog.pdfIn PDF document text
    • http://alarmy-kamery24.pl/userfiles/file/bomagusef.pdfIn PDF document text
    • http://gokea.org/upload/editor/files/tifomakolonigemuwamixozev.pdfIn PDF document text
    • http://xn--72c7caerxx0d3a9eve.com/UserFiles/File/819755502.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1607a80409def9---bibikuxuzonat.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/72c7b5c3c67ea97ec53772d5fb31e6e3/lezazakuwepovuzevusemaz.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/f6fa1acd250eb2e0c2c4e2e410651b5b/53605165008.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/b9a807f1e68bf13c2c3f517a8814ab30/19866366765.pdfIn PDF document text
    • http://anadolumatbaa42.com/genelresimler/file/vimerul.pdfIn PDF document text
    • http://eksan-ltd.com/userfiles/file/26759322108.pdfIn PDF document text
    • http://amindoost.ir/images/upload/files/63123927414.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160e49f22e0bf4---xaxepilodigufulagi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=auxiliary+verbs+english+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_off0000dfee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f805.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF805 11064 bytes
SHA-256: c48c3025a92b37cd854e0870c0a84f19575a478d15e950a433852fd4038864a5
font_02_sfnt_off0001114a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1114A 17116 bytes
SHA-256: 9fb7e7ea35e640c65dfe1d71fb59ea97da8d693abbba10bea18546e56eededa1