Malicious PDF — malware analysis report

Static analysis result for SHA-256 255882edfff3dc87…

MALICIOUS

PDF

88.1 KB Created: 2021-07-16 18:48:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8d42ceb7716f301a769fcc23b2715ea0 SHA-1: 606a66f7aa2f2d411b8ed0a6daa7a86c6b21b4a7 SHA-256: 255882edfff3dc87632b2ad91d8bb45ee455268f41c16e8e63179e0851239c37
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many of which point to compromised WordPress sites, indicating a link farm designed to redirect users. ClamAV detected this file as 'Pdf.Phishing.Trojan', and ML classifiers also flagged it as malicious. The presence of multiple external URIs and link farm heuristics strongly suggests a phishing or redirection attack, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d80031a69a---xedexatewoxotiwoba.pdf In PDF document text
    • http://exclusivelimoservice.com/ckfinder/userfiles/files/95503145374.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/sexezusepupidufumilusili.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/mazane.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/4b3c1720eb0ecab53629bf1dd94978ab/16362559934.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1606e6f4e5bf59---5871311165.pdfIn PDF document text
    • https://advantagelic.com/singhania/downloads/file/26269766220.pdfIn PDF document text
    • http://richiefamilyreunion.com/clients/7/7d/7d03816b951c94fc7c065ced7c7ccdcd/File/guxixiredenoxepasem.pdfIn PDF document text
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/ea599rktgc3chqp7e0988t57to/13435122955.pdfIn PDF document text
    • http://thuephotocopytaihanoi.com/upload/files/91724808530.pdfIn PDF document text
    • http://fanti-fitness.pl/uploads/assets/file/vasafovisakonuweroxixavu.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/cchdns0bhb434drcga12c8dpj5/14936796289.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608c4ca92e268---suxuvimupofizeful.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8f531f80d---98115491643.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607e951e595ba---47446091008.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/68922318619.pdfIn PDF document text
    • https://corpusbg.com/files/fck/file/gajoxeke.pdfIn PDF document text
    • http://wawabed.pl/uploads/userfiles/file/muxivukejirab.pdfIn PDF document text
    • https://t2sc.me/userfiles/6957256792.pdfIn PDF document text
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8725e0088---70742035502.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160b12f97d9d81---makoxusogugisawedijujowa.pdfIn PDF document text
    • https://kultmotor.hu/images/files/pibuveka.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c5a3e90afe7---rezujepixajizadarisu.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/10b7b7kii1pq19g5vqnq7j5l81/polazaw.pdfIn PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/ofl2ascucb0qd2680knkha96i0/gitezusanixeboku.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=computer+application+in+pharmaceutical+research+and+development+book+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_off0000f29a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF29A 17552 bytes
SHA-256: 4e64b3e55c406b6d45a2f22d5ea329d365ffcc8dc9c1574ebb3a7691eca15e35
font_01_sfnt_off00011fc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FC3 11316 bytes
SHA-256: eb41c70aa1e5749a7fcec3fd6c4b2fb0e1b378432ab9f69fb8412d35d491a1dd
font_02_sfnt_off000139f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1