Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cec5bbe72fbe3a7…

MALICIOUS

PDF

76.4 KB Created: 2021-02-10 16:43:24 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 27db6642d59700b2598ae4e4b2972e4d SHA-1: 2df8a0f84dd661c5f08a68787cefa13ba6b3fbab SHA-256: 8cec5bbe72fbe3a79fc784ef86beefa2535091aa3f7f5c6bdbf613cc5a3dd88e
186 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm with numerous external URIs. The document body, though heavily obfuscated, contains references to 'reading comprehension multiple choice questions worksheets' and is generated by wkhtmltopdf, suggesting a lure to disguise the malicious intent. The primary attack pattern involves redirecting users through a farm of disposable domains to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://jottigo.ru/aws?utm_term=reading+comprehension+multiple+choice+questions+worksheets PDF link annotation
    • http://kosolibanun.iblogger.org/factorising_quadratics_with_a_coefficient_worksheet_tes.pdfIn PDF document text
    • https://kufudazasa.weebly.com/uploads/1/3/4/6/134626120/952a837029b.pdfIn PDF document text
    • https://sanokigoj.weebly.com/uploads/1/3/4/8/134863934/340e534ceb6.pdfIn PDF document text
    • http://letnesil.xyz/high_school_basketball_free_throw_distanceb764k.pdfIn PDF document text
    • https://jazujopu.weebly.com/uploads/1/3/0/8/130873842/74fa25857d.pdfIn PDF document text
    • http://freedate18.xyz/factorization_worksheets_freefactorization_worksheets_free9xie9.pdfIn PDF document text
    • https://risimapi.weebly.com/uploads/1/3/4/3/134321435/bukatij.pdfIn PDF document text
    • http://infokurs.design/30934752297ah5zm.pdfIn PDF document text
    • http://nepifumawal.22web.org/playstation_2_controller_pc_driver.pdfIn PDF document text
    • https://sizomejuxitiz.weebly.com/uploads/1/3/4/7/134748976/be7bb0.pdfIn PDF document text
    • https://fosuwelu.weebly.com/uploads/1/3/2/6/132695698/5c331580.pdfIn PDF document text
    • http://freshka.fun/furia_de_titas_2_completo_dubladon7t32.pdfIn PDF document text
    • http://baykamif.space/96624403145s7bb8.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/nilititonawafim/antrenmanlarla_matematik_4._kitap_indir.pdfIn PDF document text
    • https://s3.amazonaws.com/samopakamefap/graphic_organizer_for_vocabulary.pdfIn PDF document text
    • http://fegidil.rf.gd/43868531394.pdfIn PDF document text
    • http://dazoxamawix.rf.gd/child_labor_images.pdfIn PDF document text
    • http://pimorem.epizy.com/adenocarcinoma_in_situ_cervix_patient_information.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_off0000ebbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBBB 5776 bytes
SHA-256: b3e1861ddb19d3021ba0ca5bb3399a356c5b7e17f92e61c6872042e1c3062bc3
font_01_sfnt_off0000ff4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF4D 10776 bytes
SHA-256: 48b90db88f5bb22f43bbed8b9a74dae545bf6bbbc0736fa89c13b4c152241a15

Open this report in the interactive analyzer, or submit your own file for analysis.