Malicious PDF — malware analysis report

Static analysis result for SHA-256 21dc66f815615516…

MALICIOUS

PDF

77.4 KB Created: 2021-03-16 22:13:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 2a2e25d59b11d8eb85cf3d4fcd0b4b40 SHA-1: 2371ace113d199a665c88f20ff1ffcb1907c1640 SHA-256: 21dc66f815615516177931492b45eb67a98e5092f93ada53f994b5dad1262042
184 Risk Score

Malware Insights

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

The PDF contains multiple embedded URLs, with at least one identified as a malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links suggest it's designed to lure users to malicious sites, aligning with spearphishing attachment tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • 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 links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://crophysi.ru/wix?keyword=school+excuse+letter In PDF document text
    • http://flylovel.com/5978803245lgeds.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392452/normal_5fd314f0488fb.pdfIn PDF document text
    • http://avto-trokot.xyz/whats_on_dominos_philly_steak_pizza7820h.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448347/normal_6012b22e6ac1a.pdfIn PDF document text
    • http://zukesijinizik.mywebcommunity.org/base_plate_design_aisc.pdfIn PDF document text
    • https://cdn.sqhk.co/waketeni/idQjj0N/53978017426.pdfIn PDF document text
    • http://nurokojo.mypressonline.com/my_forbidden_face_online_book_free.pdfIn PDF document text
    • https://lirefabagobaxi.weebly.com/uploads/1/3/4/0/134012393/duwegipikujus-pemuxufusaj-bomif-jobusefatorew.pdfIn PDF document text
    • http://lojapidabud.mypressonline.com/famobobilazevaxuta.pdfIn PDF document text
    • http://levelupguild.com/poloturibemopijufukofunieobv.pdfIn PDF document text
    • https://cdn.sqhk.co/joziroluxu/3jjhf8W/98837770003.pdfIn PDF document text
    • http://forsage.pw/76617911965qg3cd.pdfIn PDF document text
    • http://begemotiks.space/52781975209z2yrb.pdfIn PDF document text
    • http://moradudipomibo.mypressonline.com/does_the_navy_have_chief_warrant_officers.pdfIn PDF document text
    • https://dutilugamon.weebly.com/uploads/1/3/5/3/135301630/df2e8f2f4f4612b.pdfIn PDF document text
    • http://luxasireku.sportsontheweb.net/rootsmagic_7_registration_key.pdfIn PDF document text
    • https://nurosizakudagag.weebly.com/uploads/1/3/4/6/134699554/ponub-lasexewilujenop.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465393/normal_5fe6b29ede136.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386836/normal_6009d9a1a98ef.pdfIn PDF document text
    • https://cdn.sqhk.co/mujekesire/2ghFcBE/disney_princess_dress_up_shoes_uk.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://milebulijulami.onlinewebshop.net/descargar_cazadores_de_sombras_pelicula_completa_en_espaol_latino.pdfIn PDF document text
    • http://tumobuwixakeg.atwebpages.com/carruthers_organic_chemistry.pdfIn PDF document text
    • http://kadoxosin.atwebpages.com/mitexevulikima.pdfIn PDF document text
    • http://vupaguriwedizid.atwebpages.com/24921739533.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_off0000f3be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3BE 4848 bytes
SHA-256: 5af7369e328561e7c1599a934d09b5a1e8de120a4474eb8b9473aba3f484df1f
font_01_sfnt_off0001043b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1043B 10588 bytes
SHA-256: b744b66e692db5fe2211359766a98fe35555c59a9b6a7681ec9aefcb10d218a5