Malicious PDF — malware analysis report

Static analysis result for SHA-256 4015d3b6fed2f813…

MALICIOUS

PDF

76.6 KB Created: 2021-05-04 09:01:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: dc948555ac51cf58e89294bf055e30dc SHA-1: 5422a21600892eea48a75fd3a34ed168dadf6ffd SHA-256: 4015d3b6fed2f813e73d198a5ceb88b219f5812039044a50cd1f4ece7a887aeb
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://crophysi.ru/strik?utm_term=frederick+municipal+forest+off-road+trail PDF link annotation
    • https://cdn.sqhk.co/kuwusemob/hgjfEja/pdf_annotator_free_portable.pdfIn PDF document text
    • http://excellent-spb.ru/cmca_exam_study_guidec4vta.pdfIn PDF document text
    • https://cdn.sqhk.co/xugufufifo/idugjij/33733026437.pdfIn PDF document text
    • http://bio-ita.fun/medical_certificate_format_for_admission18mka.pdfIn PDF document text
    • http://gakukuketisalum.scienceontheweb.net/bardo_thodol_free.pdfIn PDF document text
    • https://nezikuwetop.weebly.com/uploads/1/3/5/3/135346993/xilodaxej_fabimasejarul_fefuvaru_molikokep.pdfIn PDF document text
    • http://nigemutekilum.mypressonline.com/free_printable_blank_bingo_cards_for_teachers.pdfIn PDF document text
    • http://cafe-cok.ru/lamujadogenibilisetatowiozxda.pdfIn PDF document text
    • http://trendmobile.ru/tamasha_full_movie_hd_worldfree4umzqbn.pdfIn PDF document text
    • https://mobofapewapo.weebly.com/uploads/1/3/5/3/135399527/3cb525292077899.pdfIn PDF document text
    • https://bididanigatozum.weebly.com/uploads/1/3/4/3/134314142/jolekasuni_kofelukagobil_pobusovugabem.pdfIn PDF document text
    • https://cdn.sqhk.co/ribobujir/eRliej7/epson_iprint_pour_windows_7.pdfIn PDF document text
    • https://cdn.sqhk.co/kajutizikodu/fvifmjd/jubixutirakojewigigovo.pdfIn PDF document text
    • https://lizekolu.weebly.com/uploads/1/3/1/3/131379949/3aee0c7d85.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://bd7a0a6f-bbfd-49cc-ba41-c3f2778102d9.filesusr.com/ugd/9ea91e_e5cdb56f38e746d1942fd46e3d591331.pdf?index=trueIn PDF document text
    • https://4779f2f8-a33e-4327-9c78-21ee0bcf4620.filesusr.com/ugd/31bf02_bdbb317780cf44748cd5a1c45a8619d9.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/sifawekujiki/bezimijuwevepedi.pdfIn PDF document text
    • https://s3.amazonaws.com/jokotaziweluge/44567424591.pdfIn PDF document text
    • https://1ce8651a-bfbb-4b9a-b1bf-24b3b574775a.filesusr.com/ugd/ac72e0_5997a7dd63384e969939dc6ccd74768e.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/lokijuronig/7708990866.pdfIn PDF document text
    • https://5634f520-c25d-421d-ab67-3d94505d13cb.filesusr.com/ugd/1b85ab_5387daa700964047b69b767dc64e831b.pdf?index=trueIn 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_off0000eba4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA4 5352 bytes
SHA-256: 8a10833b5421d77cde0b3536c5880d29ce152efea496ecb6877ead8f46e1b376
font_01_sfnt_off0000fdce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDCE 11280 bytes
SHA-256: 60e1c86c0fe2989f311376002bedebb7635256dfd614d305d8191d5bdab4709c