Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b0c9b4e2f61fb2d…

MALICIOUS

PDF

77.7 KB Created: 2021-10-08 16:36:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 4286c6c865d7d3669f38f7e48647e493 SHA-1: f75d95bafc0cbf5c48d5e74bbc5f5ee365f4bdb0 SHA-256: 4b0c9b4e2f61fb2d6685f2ecf7c15f3b933b7419dc726cd28341becf63d73bc5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. The presence of multiple external URIs and link farm heuristics confirms the document's primary function is to lead users to external, potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

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 https://irlanc.ru/uplcv?utm_term=puffin+browser+pc+free+version PDF link annotation
    • http://nakajima-ya.com/user_data/image/file/94701148276.pdfIn PDF document text
    • http://3e3i.com/UserFiles/file///nexemaziw.pdfIn PDF document text
    • http://boxerdapolenta.com/cmsimple/images/file/66015445698.pdfIn PDF document text
    • http://omeofest.eu/userfiles/files/19053227781.pdfIn PDF document text
    • http://losangeles.songhakbbq.com/uploads/files/kamumewijikuwose.pdfIn PDF document text
    • https://yk-tech.com.tw/ckfinder/uploads/ckfiles/files/12113499174.pdfIn PDF document text
    • http://cathugo.de/res/wysiwyg/file/mogivejonanewubidetuz.pdfIn PDF document text
    • http://simsvizag.com/admin/uploadedfiles/file///davanamake.pdfIn PDF document text
    • http://studiomarcheluzzo.it/userfiles/files/boropevis.pdfIn PDF document text
    • http://www.satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/zukulixegug.pdfIn PDF document text
    • http://xn--80aa5alfu.kz/file/80242837068.pdfIn PDF document text
    • http://mylodge-naoshima.com/images/blog/file/zexaloji.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d94b9e8a30---xokilufe.pdfIn PDF document text
    • http://wawabed.pl/uploads/userfiles/file/12488594769.pdfIn PDF document text
    • http://ingegneriarossi.it/userfiles/files/13468825338.pdfIn PDF document text
    • https://mpksieradz.pl/upload/file/lepamod.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed46216a5f---nitulokemorifosiworanabu.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/7dqkcl0bsb3d6pvav1c8q69o1e/92134110596.pdfIn PDF document text
    • http://btfa.tw/upload/files/98075336086.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/2505661660.pdfIn PDF document text
    • https://posh.hr/files/zigegorilegawotexodagit.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/49669878229.pdfIn PDF document text
    • https://agregadoschucuri.sinecsas.com/ckfinder/userfiles/files/96542354071.pdfIn PDF document text
    • http://eco-building.cz/UserFiles/File/86428875251.pdfIn PDF document text
    • https://bgg.pirkitpadangas.lt/ckfinder/userfiles/files/70444589310.pdfIn PDF document text
    • http://athaj2.specialty-match.com/upload/files/poritotuvobekesexigeme.pdfIn PDF document text
    • http://www.farimar.pt/imgs/uploads/gukamudujuwokedax.pdfIn PDF document text
    • 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_off0000c99a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC99A 18176 bytes
SHA-256: 7303feccba14913f0c3bd68fa591f9189a1e3428258681283e127901c190ad0b
font_01_sfnt_off0000f8ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011105.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11105 10560 bytes
SHA-256: 3f4074167176d1fbdf41100a879b301d7d2e21757768ffd08cd29573a5d213cc