Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3435e0853c0b1e3…

MALICIOUS

PDF

75.9 KB Created: 2021-04-05 15:51:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: a8e34bf2664657a89f7d7790322ae7ce SHA-1: ce5638cd2aa4cdae8a73d424b649c4e4d083a8b8 SHA-256: f3435e0853c0b1e3b3e56931926dcad253c4d663dd3acc6df1b13766cb0b14db
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains a large number of external links, many pointing to disposable domains, suggesting it functions as a link farm. The primary malicious URL identified is https://midufefew.ru/123, which is likely used to redirect users to malicious content or phishing sites. No scripts were extracted, but the PDF structure and link farm heuristic indicate a malicious intent to direct users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://midufefew.ru/123?utm_term=subordinating+conjunctions+worksheet+6th+grade+pdf PDF link annotation
    • https://denudosija.weebly.com/uploads/1/3/4/0/134017010/zavisipapule-xajeragizaxup-zuvifor-pefewezog.pdfIn PDF document text
    • https://mitegasur.weebly.com/uploads/1/3/1/8/131871816/1364010.pdfIn PDF document text
    • https://mejotowud.weebly.com/uploads/1/3/0/9/130969644/06f9bc55532c.pdfIn PDF document text
    • https://marotebage.weebly.com/uploads/1/3/4/7/134712984/pibidijatejunupajo.pdfIn PDF document text
    • https://fumabufoduf.weebly.com/uploads/1/3/5/3/135313851/e05dc91a0af.pdfIn PDF document text
    • https://nijupafubowawiz.weebly.com/uploads/1/3/4/0/134012726/vuzakewomeba-tilidufor-tijimokuzewa-somesavelojenu.pdfIn PDF document text
    • https://linajijokib.weebly.com/uploads/1/3/4/0/134000065/00ddbb6d676c37.pdfIn PDF document text
    • https://monirazosakazux.weebly.com/uploads/1/3/5/3/135316997/pudotiwitewetilugu.pdfIn PDF document text
    • http://folugomobok.getenjoyment.net/rti_application_form_punjab.pdfIn PDF document text
    • https://kajipeluvo.weebly.com/uploads/1/3/4/3/134318391/xizoxigu.pdfIn PDF document text
    • https://sakobapo.weebly.com/uploads/1/3/3/9/133999770/xovepikel_movukeju_dofijidunudoxok_nedikiv.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/a08dc318-be66-4fb3-bdd6-db8066131f47/dirty_christmas_song_lyrics.pdfIn PDF document text
    • https://fe2b84af-b373-48e0-a714-f820169e3fe9.filesusr.com/ugd/ed1d2e_6c7917a04add48bab9a94b2648777c30.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7b546a37-041d-4d1a-8694-9ddfc9378d34/prentice_hall_gold_algebra_1_teaching_resources.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bb67be3e-af0d-4ec0-9dc1-6f605ebfb168/91461992707.pdfIn PDF document text
    • https://9005981c-20a7-4b93-9dfe-a591c0bc6fcf.filesusr.com/ugd/afbba5_e0df0ad7f53e4a12957a9dfce5bc54ca.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xamibebulosaxug/4018686881.pdfIn PDF document text
    • https://s3.amazonaws.com/wotodedaruzuk/100372311.pdfIn PDF document text
    • http://mejumobax.atwebpages.com/genesis_de_la_nacion_monarquia_federalismo_y_centralismo.pdfIn PDF document text
    • https://s3.amazonaws.com/xulepiwa/81582838141.pdfIn PDF document text
    • http://domuromu.atwebpages.com/catalogo_importados_price_shoes.pdfIn PDF document text
    • https://48e4e0df-78ce-4736-8797-27735e68dc67.filesusr.com/ugd/f3b179_3d32a64f95344c3f91ceeedbba8a703d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/16f605ae-309e-4ab7-9a97-5ea27540f8d2/chemical_engineering_thermodynamics_lecture_notesppt.pdfIn PDF document text
    • http://buwifojozoziden.atwebpages.com/22035544.pdfIn PDF document text
    • https://s3.amazonaws.com/rikolesafuwofar/cholamandalam_vehicle_insurance_policy.pdfIn PDF document text
    • https://s3.amazonaws.com/dinisemowoge/mail_format_for_sending_cv_to_hr.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_off0000e922.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE922 6016 bytes
SHA-256: 9456cf08daf500c48aba6a7758d3b61ba62fc9001a45907fe6d81d15cc1a49d2
font_01_sfnt_off0000fda7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDA7 10452 bytes
SHA-256: 2e2b0b76e0ff90cda4a1b835c59730fc3194ab845f337e8273962f2f3f1744f0