Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf355b96e68aa90a…

MALICIOUS

PDF

70.7 KB Created: 2021-05-28 08:57:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 05a08b143b63cc97a12984e5d1759b83 SHA-1: 921fcd217331f1568db64b51c5e737cf75c55a45 SHA-256: cf355b96e68aa90a23a2ac47d245a89e1a76e6db179e61193b770005e257d936
186 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

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

The PDF file is identified as malicious by both ML classification and ClamAV, with a specific detection of 'Pdf.Phishing.Trojan'. It contains a large number of embedded external links, many pointing to disposable hosting services, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, appears to be a lure related to a textbook solution manual, which is a common tactic for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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
  • 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://kuzutuzo.ru/strik?utm_term=solucionario+fisica+2o+bachillerato+mc+graw+hill PDF link annotation
    • https://bobujiwa.weebly.com/uploads/1/3/1/0/131070874/2145546.pdfIn PDF document text
    • https://fupomojokom.weebly.com/uploads/1/3/4/4/134458651/75de2fe4d0aeb3.pdfIn PDF document text
    • https://guxovegetixewaz.weebly.com/uploads/1/3/2/3/132302910/muwasisonodejopila.pdfIn PDF document text
    • https://kexulisil.weebly.com/uploads/1/3/4/7/134762119/kasuwopas_dexozamonipurav_ladugewi_jibegapir.pdfIn PDF document text
    • https://fukagopesuzidad.weebly.com/uploads/1/3/1/3/131381553/webimotabajitelemasa.pdfIn PDF document text
    • https://nusomosuguxapo.weebly.com/uploads/1/3/4/6/134693055/1b4d6347eae5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4410030/normal_5febdb51be121.pdfIn PDF document text
    • https://popajilosofov.weebly.com/uploads/1/3/0/7/130776408/vajakade-gazobewol-sujunotisaponiz-lajofofutojimov.pdfIn PDF document text
    • https://neziraninev.weebly.com/uploads/1/3/4/5/134502601/diwubigevum-jovosizi.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4444864/normal_5fd05f0db54aa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407314/normal_6067993dd56a6.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/038f4ede-3423-4d88-9f25-8d8eea759969/tercera_ley_de_newton_accion_y_reaccion_formula.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4dd37f29-772d-4a18-91f9-98dff33e5654/62403670665.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/01da7c43-d9f2-4483-9652-5acdb9470def/diary_of_a_wimpy_kid_rodrick_rules_archive.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d3b4f26f-2652-456c-b3f5-8bb512902eff/73796294842.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c652b0c0-0f62-4a87-84df-e9654f36378e/totejexobonudadibe.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/68d5942b-eb13-480c-bfd6-faf315fad45c/how_to_get_ge_washer_to_deep_fill.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eb262b63-3e77-4e53-b351-bf98a7dfdf39/exam_vocabulary_builder_android_app.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a8050ae1-f846-4e34-a5da-7620dc8ac10b/jevaxevawozin.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/26646e03-d305-4898-99fa-d27b7a90e853/14062833081.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cbe887f7-5ccd-4d60-8e19-20da73bd0f7f/sparknotes_hamlet_act_2_scene_2_summary.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3647f015-cfd9-47b9-bd8f-1f340ab255d1/how_to_change_honeywell_3_port_valve.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/26caddbd-c32a-435a-aee5-13fe9f8e4a24/86616193310.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0f228ded-8850-4125-8f82-74737658df24/bupun.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_off0000d088.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD088 5764 bytes
SHA-256: ac02b429f8cbe3065639cd49bb5525eedbfe96a315d299b2dd8c1cf508b5c36d
font_01_sfnt_off0000e417.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE417 12080 bytes
SHA-256: ceb58c662061f04b9dabee6ec3ff40795e3f00435086599826c8d0168d7efb00

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