Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b4406c12c5b9122…

MALICIOUS

PDF

85.4 KB Created: 2021-06-28 05:52:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ab781e184bc7f238f45b5055e1197963 SHA-1: 9698b466e1484d05d836c11d78a639f526f81a8e SHA-256: 8b4406c12c5b91225d8e736e5d639ca3d7ce6ec0340c3f302ec9c5665b37ce8e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous links, many pointing to compromised WordPress sites and disposable domains, suggesting a link farm designed to lure users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this assessment. No scripts were extracted, but the overall structure and URL distribution indicate a phishing or malware distribution attempt.

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 https://synerhu.ru/uplcv?utm_term=collect+and+organize+data+worksheets+4th+grade
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bdc45550f34---volatikolipadudawu.pdf
    • https://dvg.asia/ckfinder/uploadfiles/files/34173586576.pdf
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/a9708b85eb0b1b54307ac05749b96936/59440606006.pdf
    • https://poolpoint.be/uploads/file/fexeju.pdf
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082cb0ddd27d---75462094072.pdf
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/pvfhl7ruehpo3tar123as35f53/febogudutu.pdf
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079e245d774d---tapopiboz.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a3e4e4e3d1---96357078111.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b20c6c0e0c---goritisibu.pdf
    • http://cedule-plachty.cz/files/file/telomeze.pdf
    • https://urbanplace.me/wp-content/plugins/super-forms/uploads/php/files/aa607695f8d96575a2d34e1d244f87d8/kexiburubeb.pdf
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/8sqhukvt1bcmlk52qa67gg9ds1/98057033697.pdf
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/160854461065db---2198996740.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084767e53d3d---dovovejowip.pdf
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609295d3a915c---87608586233.pdf
    • http://ankaser.com/userfiles/file/tajakuzusawazixamido.pdf
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/de42566j614uq6eujtmbiqkbe2/87809408076.pdf
    • http://cayxaotamphan.net/userfiles/image/file/ximumodigaxekurusom.pdf
    • http://hpworld.hu/data/pic/Image/file/40873497563.pdf
    • http://chonburi33.com/userfiles/file/kogijagokowenoso.pdf
    • http://eltonltd.ru/sites/default/files/uploads/zigumubirobi.pdf
    • https://bwawarszawa.pl/upload/file/tabigibubogosumebenavuru.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160931d5887a74---varukupavinimirafime.pdf
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1608b7015aee09---29614617062.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ead6.bin
5b02f5f3b444bfd999d64144ac8b6f7f08dd4d3d188b35851cbec0d6afa945db
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD6 16848 bytes
font_01_sfnt_off00011690.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11690 16792 bytes
font_02_sfnt_off00012ea7.bin
9e74564e697d19c92e764147bc8adf94f67da6d88025e17480b957d428f229d7
pdf-font-stream PDF embedded font (sfnt) at offset 0x12EA7 10996 bytes