Malicious PDF — malware analysis report

Static analysis result for SHA-256 85d9a39a1fe8d155…

MALICIOUS

PDF

69.3 KB Created: 2021-09-25 19:32:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1e760f3fe66a4f963f7bebaf7030b6b8 SHA-1: 4cd7a5c1ea9010c7ca9c83840cd3a46826b05e9b SHA-256: 85d9a39a1fe8d1555ae3b84c1560f1acea82e783a471372eda241d13db01a6cd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous links, many pointing to compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and link farm nature are indicative of phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://gbfrjournal.org/pds/userfiles/files/7558551616.pdf In PDF document text
    • https://advantage.ee/media/contents/file/16614626487.pdfIn PDF document text
    • https://clubon.top/uploads/files/betilokonadexatavorumuk.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130eee62e671---19918346618.pdfIn PDF document text
    • http://ucinnovation.ru/admin/ckfinder/userfiles/files/pajapenabi.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/af53153c78088793d650b8e4fd311e7e/vivepowokape.pdfIn PDF document text
    • https://fruitssupplier.com/app/webroot/img/files/melirebipuvizaz.pdfIn PDF document text
    • https://wasael.com/userfiles/file/zubaginemuro.pdfIn PDF document text
    • https://cosmopolitanhotel.lastrada.bg/uploads/wysiwyg/files/92277604564.pdfIn PDF document text
    • http://sushigonewildtogo.com/uploads/files/linebifabusajemibolax.pdfIn PDF document text
    • http://schokofontaene.de/idata/gilekimitedeso.pdfIn PDF document text
    • https://soudurelauziere.com/upload/editor/file/97426259573.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/161374756783f7---22675805566.pdfIn PDF document text
    • http://optykglowacki.pl/obrazki/files/55001711083.pdfIn PDF document text
    • https://postelezmasivu-zlin.cz/ckfinder/userfiles/files/vilivulof.pdfIn PDF document text
    • https://ppkh.net/userfiles/file/36140672709.pdfIn PDF document text
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16136d4d247f61---72570439627.pdfIn PDF document text
    • http://mudrberanova.cz/userfiles/file/gilepuzudezuwimikudeku.pdfIn PDF document text
    • https://chorland-dining.com/webroot/editor-uploads/files/50794530218.pdfIn PDF document text
    • https://journalofcritique.com/ckdosyalari/upload/files/88120478780.pdfIn PDF document text
    • http://skncn.com/u/files/86889453912.pdfIn PDF document text
    • http://mmprogetti.it/userfiles/files/54786528648.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109062132476027.pdfIn PDF document text
    • http://ptairsupply.com/userfiles/file/ludojojeraso.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=fifa+21+offline+androidPDF 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_off0000b059.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB059 10232 bytes
SHA-256: 399a8544bad077a22cd4c18d304e6267130410185c0e0514fa51c25bdbaf29ef
font_01_sfnt_off0000c766.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC766 15936 bytes
SHA-256: 7fd3fec7787b097c1caf9ca81dd3a83383102ac6e29019285feb18e4214c8e7c
font_02_sfnt_off0000f000.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF000 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1