Malicious PDF — malware analysis report

Static analysis result for SHA-256 21fbcbfb5b4242cd…

MALICIOUS

PDF

83.4 KB Created: 2021-03-14 16:53:57 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-07
MD5: 6638cf1bb468304dab4cc650d2ab70e2 SHA-1: b18f9829bbb3a93719fb10fed231251725d2e6ae SHA-256: 21fbcbfb5b4242cdc2f1b4c189c473c9984003d3262baff67c5babf049bcc43b
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file contains a large number of external links, many of which point to disposable domains and are likely part of a link farm designed to manipulate search engine results or redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The embedded URLs and the PDF's structure suggest it's used to drive traffic to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://botokaw.ru/strik?utm_term=what+size+bobcat+should+i+buy PDF link annotation
    • http://bitcoinchat.fun/10764357806gue62.pdfIn PDF document text
    • http://hargotel.xyz/74238376567ivus5.pdfIn PDF document text
    • http://lobulezinovux.medianewsonline.com/jasumififirelel.pdfIn PDF document text
    • http://discount50it.pro/never_eat_alone_wikipedia9jhx3.pdfIn PDF document text
    • http://wogunowesok.22web.org/96718284153.pdfIn PDF document text
    • http://boxijogirexu.medianewsonline.com/twilight_book_cover_collection.pdfIn PDF document text
    • http://flowerport.store/how_to_conduct_environmental_impact_assessmentr0r7p.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wugujub.onlinewebshop.net/imac_user_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eed149f0-b514-4842-9493-b3cffb97a9a4/the_2nd_edition_of_bergeys_manual_of_systematic_bacteriology_is_largely_based_on_classification.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b567f954-7023-464c-9e69-48e1968583ab/dnd_dice_number_meaning.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/155aadb1-f1b0-4774-b798-65e4feb962d9/cursos_de_ingles_en_linea_certificados_gratis.pdfIn PDF document text
    • http://rusakarazixano.epizy.com/besujewabeguxezirexasuv.pdfIn PDF document text
    • https://123949be-7110-4ba3-a240-a7df06fb38ce.filesusr.com/ugd/80fd5d_0776ebe4ab724ca3971f33186b639ac9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f5f82262-6f21-480a-a088-537642ad7b1b/what_does_f34_mean_on_a_thermador_oven.pdfIn PDF document text
    • http://pexomesukifek.epizy.com/dexukugixozonujagoravoku.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b39a802a-d9b3-4461-88e3-dacc4b71505f/5230813367.pdfIn PDF document text
    • https://f6ce3cfb-f922-470c-9e0e-eaf724001b0e.filesusr.com/ugd/defcb2_ec45b185fe5f41099fce57b0dd4c51b8.pdf?index=trueIn PDF document text
    • http://lafagelupuf.myartsonline.com/91384945311.pdfIn PDF document text
    • http://xaramoturowuf.rf.gd/is_hem_ankle_rehab_legit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/74211fdc-dd64-40e7-b16d-dd6159ca9412/hp_laserjet_1012_driver_mac_catalina.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d28b6bf2-780b-47ce-884a-a0e7c678d87d/general_to_specific_words_examples.pdfIn PDF document text
    • http://kexomun.myartsonline.com/gizuretix.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000108c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108C2 5236 bytes
SHA-256: 66633fe9837a48f7b6f07e1b4d52bd21d8b4982eef4df8f11da45a6b688d731e
font_01_sfnt_off00011aaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AAA 11036 bytes
SHA-256: d0acadf9b9a6c65b2a164edcf6a051f3a98fdb39436a93d14c4011d6530f8435