Malicious PDF — malware analysis report

Static analysis result for SHA-256 d636f04394de27b9…

MALICIOUS

PDF

84.1 KB Created: 2021-06-09 22:39:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 807cb8292238534ffa80516ebd3f4659 SHA-1: 683908a905fac8fbfd076803f1ba2088272695e2 SHA-256: d636f04394de27b968ec6801f364d226153fb075cdd98c156bc7d7f63a294ce4
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, identified as a link farm, with the primary URL being zajinet.ru. The ML classifier and ClamAV heuristic strongly indicate maliciousness, classifying it as a phishing trojan. While no scripts were directly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://zajinet.ru/123?utm_term=html+tags+pdf+file+free PDF link annotation
    • https://fozirufimagez.weebly.com/uploads/1/3/0/9/130969558/b8c2a223592c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4425009/normal_5fefe0146b429.pdfIn PDF document text
    • https://nilozirarita.weebly.com/uploads/1/3/4/4/134463528/3339570.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387567/normal_600c7bd9942e0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420906/normal_5fd26564a19af.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/5b8667a9-b095-4cfc-a7a5-c6057047442b/dejul.pdfIn PDF document text
    • http://lijegazoz.pbworks.com/w/file/fetch/144417252/pujexifanewonemivorefefoz.pdfIn PDF document text
    • http://noxiwako.pbworks.com/f/14227138518.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e665d658-8e5e-4ffb-86a4-853eaafc2e23/wakenob.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a950f6a1-ec70-4605-a086-962364e537e1/xukazogiwapa.pdfIn PDF document text
    • http://sofutikajen.pbworks.com/f/www_mp4_converter_com_video_converter_com.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6fa3ceba-2431-4b47-9879-0c0c800803ab/norton_anthology_of_american_literature_1865_to_present.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4d9b6239-4ca8-4896-89fc-307989dd5b58/butelobe.pdfIn PDF document text
    • http://kunozulig.pbworks.com/f/how_to_write_up_a_lease_renewal.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6a1505f3-49e4-4982-b2bb-089a0e078416/sixireroputubiwadez.pdfIn PDF document text
    • http://fokopaviwu.pbworks.com/f/rasosawevez.pdfIn PDF document text
    • http://lodedeti.pbworks.com/w/file/fetch/144653418/baixar_video_openload_online.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5485f586-6578-4f29-96aa-c66bc071c178/navy_new_pt_standards.pdfIn PDF document text
    • http://werinenimuta.pbworks.com/f/twelfth_night_folger.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ec69fe8f-2dc8-4e80-b859-84531491cb56/bevamib.pdfIn PDF document text
    • http://fadoposapat.pbworks.com/w/file/fetch/144446223/wuponadupazozopuvepabof.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ff4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF4C 4892 bytes
SHA-256: bd5bf3d0679a7739faca1337c7ebd7386f23bcd6b28545c9f9464c34a20b2db8
font_01_sfnt_off00010fed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FED 10904 bytes
SHA-256: 8aefff4520db243891befa241c56c482b19012cc0b3a91bb2503b9e45b3ae238
font_02_sfnt_off00013536.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13536 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3