Malicious PDF — malware analysis report

Static analysis result for SHA-256 c83ff57872f21ccb…

MALICIOUS

PDF

74.2 KB Created: 2021-03-24 02:48:13 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 663a6a1b3ab0d12ec7a822576ff95704 SHA-1: 793617bf452fb4529c87924a8fa50b5fcb58989e SHA-256: c83ff57872f21ccb000f9ba3d886e49bd455eb2573ccb9196f5ea81622c15ac6
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous external links to other PDF documents, likely for SEO manipulation or to distribute further malicious content. The presence of multiple external URIs and a link farm heuristic strongly suggests this is part of a larger distribution or SEO poisoning campaign.

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://zajinet.ru/wix?keyword=nikko+stirling+gameking+4-16x44+manual PDF link annotation
    • http://keepqifi.site/makirulolufodudor7g4w.pdfIn PDF document text
    • http://sentytld.online/arctic_wind_portable_air_conditioner_manual14xc3.pdfIn PDF document text
    • https://zuxosudeti.weebly.com/uploads/1/3/4/3/134359900/rabowimejid_negugekezosenu_redidotef.pdfIn PDF document text
    • https://bezugoro.weebly.com/uploads/1/3/4/6/134697972/xagujo.pdfIn PDF document text
    • https://xogosafaxisomig.weebly.com/uploads/1/3/0/7/130739024/kopofamoz.pdfIn PDF document text
    • http://popularchoice.space/plane_simulator_2017_mod_apkqvv4x.pdfIn PDF document text
    • http://siankaanmexico.com/how_to_use_a_tailor_professional_sewing_machine4jjc0.pdfIn PDF document text
    • https://nexudusuje.weebly.com/uploads/1/3/0/7/130740550/8123441.pdfIn PDF document text
    • https://zimuroxojirewun.weebly.com/uploads/1/3/1/4/131407818/d6c8f2d0e442.pdfIn PDF document text
    • http://toportt.online/34771238287mtg0r.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/d6afeea0-7c5d-43bd-a2c3-93cc22a025b0/sowewelabuz.pdfIn PDF document text
    • http://dirulibas.onlinewebshop.net/what_is_another_word_for_first_of_all.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/790937c3-71ae-4d5d-80cd-382ae1fddc83/hp_elitedesk_800_g1_mini_user_manual.pdfIn PDF document text
    • https://68358877-4ee6-4e53-94f7-4bd9665c1f53.filesusr.com/ugd/3bbd68_c4e903acf37e41fc82944906b76d4e0f.pdf?index=trueIn PDF document text
    • http://sugamane.onlinewebshop.net/posoposezizozo.pdfIn PDF document text
    • https://d6b7b3c7-8429-4d82-9d75-5d5d09e763cc.filesusr.com/ugd/a8c229_9132588312ff4950a9c45e8d025685b4.pdf?index=trueIn PDF document text
    • https://1801fa0f-56e4-4894-8452-b8e06651d4be.filesusr.com/ugd/868401_167f7960608b492491a6c44fa1a240b9.pdf?index=trueIn PDF document text
    • https://03386fec-e341-46be-bf9f-2f2bd19f9bfe.filesusr.com/ugd/bf57b5_13c56ae6b9dd49869720fa40e8a3a48f.pdf?index=trueIn PDF document text
    • https://a540aa65-2eb1-4ac3-86d0-bf6a54daac96.filesusr.com/ugd/2d797c_45b425c69c5d4c359887066fae34e8e4.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_off0000e40d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE40D 5432 bytes
SHA-256: 62d9dfe088c944f67d17304663411394dcab5dc9c2d39698492316c786b1565b
font_01_sfnt_off0000f690.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF690 10744 bytes
SHA-256: 5b5c63ab23bf3bbcf03e1b7df208177606326bf1c1cc194a2f93672a9a12f4df