Malicious PDF — malware analysis report

Static analysis result for SHA-256 c43881b2051480bf…

MALICIOUS

PDF

84.1 KB Created: 2021-03-27 10:40:53 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 445f910ead15524fb1f9bd3a4123b222 SHA-1: 88a07edaefa343a20f16ea617a74f6aa5ef0f116 SHA-256: c43881b2051480bf8f3464d61259d06ec1b8549026380c3492e0d03af5126765
186 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm or SEO manipulation tactic. The embedded URLs likely serve to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://jacksth.ru/strik?utm_term=what+is+the+importance+of+a+keystone+species+in+an+ecosystem PDF link annotation
    • https://cdn.sqhk.co/lilaxikixo/cXbPO4a/rozefuved.pdfIn PDF document text
    • http://bivaxopepukoxi.getenjoyment.net/sample_motivation_letter_for_phd_scholarship_application.pdfIn PDF document text
    • https://dixawofira.weebly.com/uploads/1/3/5/3/135303501/vorapukufexozef_pulofutu.pdfIn PDF document text
    • http://pibarulajido.getenjoyment.net/xipef.pdfIn PDF document text
    • http://nanebaxexob.getenjoyment.net/famous_lines_from_a_river_runs_through_it.pdfIn PDF document text
    • http://bomufofo.iblogger.org/77697086109.pdfIn PDF document text
    • http://zokumujanuni.iblogger.org/what_are_three_most_common_research_methods_used_in_social_psychology.pdfIn PDF document text
    • https://wodanosivowifig.weebly.com/uploads/1/3/4/5/134593279/magiwukutale.pdfIn PDF document text
    • https://cdn.sqhk.co/zuxazutiri/ugcigC6/jakabivenovadulu.pdfIn PDF document text
    • http://ditilage.22web.org/my_phone_is_always_awake_android.pdfIn PDF document text
    • https://xuvakaxatal.weebly.com/uploads/1/3/1/0/131070170/1181033.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://59548cc9-d6a6-4b2e-bd73-2bfb7290c7b5.filesusr.com/ugd/3fd21f_34a880a6d2624ea2b6ada9d9d14b7bb0.pdf?index=trueIn PDF document text
    • http://vivusefodubelep.epizy.com/ulna_bone_anatomy.pdfIn PDF document text
    • https://9764c975-acb6-4bd5-a3ff-b1f4624bc9bc.filesusr.com/ugd/5bcb7b_260273d8c60845fbaea0107080a362f3.pdf?index=trueIn PDF document text
    • http://mijovutotukedes.onlinewebshop.net/30032303219.pdfIn PDF document text
    • https://770ad53b-b55e-4e58-b1eb-3709f41304f7.filesusr.com/ugd/98e298_7df60583c4e3478ba4de8d116a26d33c.pdf?index=trueIn PDF document text
    • https://d190c387-1498-4382-a59e-98d1a0a9794c.filesusr.com/ugd/a91264_696f1b712b634a9ca2aab5763aaa3178.pdf?index=trueIn PDF document text
    • https://911f1565-2faa-4874-b261-330d521e7362.filesusr.com/ugd/f46427_01d02ac6a7b04fc48362879b24105ba0.pdf?index=trueIn PDF document text
    • http://mezizafija.rf.gd/kevebimufuxuxowixasurafa.pdfIn PDF document text
    • http://gixarewujedel.atwebpages.com/kebufikisesi.pdfIn PDF document text
    • https://c01188fd-d8af-4b86-846b-090f7ecd58d8.filesusr.com/ugd/9058e5_2ec621ceb4d04ba0a154ec72ae87ad2d.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_off00010b85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B85 5404 bytes
SHA-256: ec2e32922231811a8e95e76e5ebf4afa9b8c7ad7e1585162b31db7d48d4e72cc
font_01_sfnt_off00011dd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DD0 10760 bytes
SHA-256: b237617bda85e875bc1f6b841c8fa61c5d10f863d20ada5a064839bf42b44908