Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d28573c880b231e…

MALICIOUS

PDF

86.7 KB Created: 2021-08-21 19:08:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d7ec34e83a062218f136cc022347c071 SHA-1: 2a3fe4ac2bd497161d4e7176ac867b9dddedfb5f SHA-256: 4d28573c880b231e6f46991f4182162c6f2228d7a3c9573424ca21f88c024507
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs that point to external websites, some of which are hosted on compromised WordPress sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather for SEO manipulation or to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://orthocarecentroortopedico.it/userfiles/files/39229868497.pdf
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a20dfd81a06---7734111560.pdf
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/7baefbcc3f77b7eba1f52963867b9337/98748497691.pdf
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fd896238bee---kowazavajaxadirovad.pdf
    • http://geredekombiservisi.com/userfiles/file/91940979390.pdf
    • http://korean-school.hu/hangul/userfiles/file/balajuvi.pdf
    • https://sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bb82fc6abb2---8219145725.pdf
    • http://tcihk.com/userfiles/51912485318.pdf
    • https://dacinsara.ro/fckfiles/file/73050944067.pdf
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088ef17bd8b1---95694291794.pdf
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb82b67336---lukob.pdf
    • http://schubert-hh.de/image/file/6347049490.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a04b36bd67e---birunelom.pdf
    • https://santchavarabed.in/ckfinder/userfiles/files/77202387160.pdf
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/24121950a61fdf90b772b8e879075cb4/jokodovirowumekelawix.pdf
    • https://uppersanduskyrotary.com/cms/files/File/xetodarurometaxevalufakod.pdf
    • http://kosmonautika.ee/ckfinder/userfiles/files/fododukenewebomowowi.pdf
    • http://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/fuxalufobafivimik.pdf
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/1608d9e01216f8---56751989259.pdf
    • http://techbis.pl/files/file/baxexawonajoxekekized.pdf
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ec2c835ada---zeparozuratubafokavuvofi.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b93fc559a4---47740761022.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=bissell+powerforce+compact+2112+filter
    • 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_off0000ebd2.bin
82fe07ba8920af26942d7b607cefdb37fca0aeb79615757fbbb67df219ab0374
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBD2 10848 bytes
font_01_sfnt_off00010520.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10520 16792 bytes
font_02_sfnt_off00011d32.bin
06ccf3868731990b0464f97f32c470ead5550edc9acb91cf630d84525663394c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D32 18128 bytes