Malicious PDF — malware analysis report

Static analysis result for SHA-256 153316103fa8f54d…

MALICIOUS

PDF

73.9 KB Created: 2021-09-11 16:47:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 38ae43aad47ed4e895212934630a74bd SHA-1: 797a6ef1c842d53c257f89fd710e408acc01a546 SHA-256: 153316103fa8f54dd3cdadad829a2f6ac114534a4d22d573649cb2374d01d774
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous links, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. The primary attack pattern observed is the use of a link farm to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://www.karelo.com/uploads/File/72286611920.pdf In PDF document text
    • http://zangerlelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/17705888586.pdfIn PDF document text
    • http://veterky.ru/ckfinder/userfiles/files/bumopu.pdfIn PDF document text
    • https://tanhoaphat.vn/userfiles/file/reridejujuzupurijaweno.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613153dbcdc02---wabomowogakuka.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139b49fe32a0---dubixoteborujutuketete.pdfIn PDF document text
    • http://studio-orlandini.com/userfiles/files/vutiv.pdfIn PDF document text
    • http://xn--80aaaaaikdebj9ccf1ayja1b5a3q.xn--p1ai/ckfinder/userfiles/files/guboramovukemurozokaze.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a207f4a470---4333711967.pdfIn PDF document text
    • http://highendschmiede.de/highendfiles/file/tajigibiwujafofonez.pdfIn PDF document text
    • http://be-now.pl/userfiles/file/dijofoxirep.pdfIn PDF document text
    • https://www.alugutader.fr/ckfinder/userfiles/files/fevigebipelakalimuf.pdfIn PDF document text
    • https://larioenergy.net/uploads/file/fuwubumotirawoginuwiniku.pdfIn PDF document text
    • https://binarbaidtrading.com/public_html/userfiles/file/pebaninamanexege.pdfIn PDF document text
    • https://aldaserwis.pl/ckfinder/userfiles/files/70931334247.pdfIn PDF document text
    • http://myoffice2561.sesao33.net/UserFiles/File/51328304346.pdfIn PDF document text
    • http://dalhousieretreat.com/cote_dor_import/admin/ckfinder/userfiles/files/bupaxipomidakobajun.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16131b92060f06---gomexav.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/16134a45fcc5f2---vorededijuma.pdfIn PDF document text
    • https://rowanmkt.com/Uploads/ckfinder/userfiles/files/3659163385.pdfIn PDF document text
    • http://cosmikkino.ru/sadm_files/57530525857.pdfIn PDF document text
    • http://faurerom.com/userfiles/file/83709348709.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=u+words+that+are+positivePDF 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_off0000c159.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC159 10496 bytes
SHA-256: caf5649d9686f2dab286d9aaeade89634c916b3d4999a8d40b525775d827cff7
font_01_sfnt_off0000d96b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD96B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f17d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF17D 16020 bytes
SHA-256: b8ae770378a20331d03382262fc993e64ffbdd8969cf7cd721909562b49845e9

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