Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb3923bffbe5840f…

MALICIOUS

PDF

80.0 KB Created: 2021-09-03 05:31:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: dec96ba82b412ac3fec75de19b4f0815 SHA-1: 24ca51d1dd2d060df1c3d33fcd24f532f9296926 SHA-256: fb3923bffbe5840f6cebb41f8e30b4aef551dcd39873b76add1788660116ebe0
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 external URLs, many hosted on domains flagged as potentially compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and does not provide direct clues, but the heuristic findings of 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' confirm the link farm's suspicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://vagtteam.dk/userfiles/Files/favugonavusegopo.pdf In PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ec417feeb92---duwalatizede.pdfIn PDF document text
    • http://gift-founder.com/archive/upload/files/lamakesi.pdfIn PDF document text
    • https://transmilenio.net/datamont/userfiles/file/74885871965.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160b82d77bda7a---55135110036.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/zenateparigikujujowu.pdfIn PDF document text
    • http://coss-wynn-reunion.com/clients/d/db/dbe3622004495b304d8703879a486b7d/File/61647004734.pdfIn PDF document text
    • http://mxm-hosting.nl/img/editor/file/62911041459.pdfIn PDF document text
    • http://reklama-kemerovo.ru/files/files/nusugadunuzobirejiwog.pdfIn PDF document text
    • http://serramentisiciliano.it/userfiles/files/43330028556.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/nudidivitomenetanaxani.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd0a6ada5e---fuzapamanixolomekuzoj.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/6e9db6e4153a0724abe7445e07ad5801/lelog.pdfIn PDF document text
    • https://fotobolfestmeny.hu/mvc/userfiles/file/91741859952.pdfIn PDF document text
    • http://paoladebenedetti.eu/userfiles/files/mebepojoduzaxulofafirew.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a063d624b91---3707476973.pdfIn PDF document text
    • https://amzentransportationindustries.com/admin/imagetemp1/file/jawixedekag.pdfIn PDF document text
    • http://asbufestival.com/uploads/FCK_files/file/33181601973.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/pvcsn7sdjtvmppts3vf9hnqn86/92094183010.pdfIn PDF document text
    • http://circolosilverblufitnessclub.eu/userfiles/files/goberu.pdfIn PDF document text
    • http://turskazka.ru/ckfinder/userfiles/files/nedivimaxepakewin.pdfIn PDF document text
    • http://natpuedu.in/userfiles/file/54498087273.pdfIn PDF document text
    • https://lightingsystemscol.com/wp-content/plugins/super-forms/uploads/php/files/7bf60a83f27b63dff020ccd294a155d3/jipafejiwi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=augustus+apixaban+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_off0000d5ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5FF 17384 bytes
SHA-256: 2c60a53f4446d79f0a2fe7f18d88f28392b9046238e3c31f371651f77bb6dc2d
font_01_sfnt_off000102db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102DB 10596 bytes
SHA-256: 35132b152cdc09c1a20bd3146d5f2c7db9db29e8e88b15f09d19732bb1cb3621
font_02_sfnt_off00011ac8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AC8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1