Malicious PDF — malware analysis report

Static analysis result for SHA-256 f854114d061407b5…

MALICIOUS

PDF

75.0 KB Created: 2021-03-25 11:56:22 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 84fbc50b861bd4386a0fb137b0b86c88 SHA-1: ce8ecf7588ac32378b3598c0c90a1ced1f9f1ee3 SHA-256: f854114d061407b53fac196b98b735e0d9b5b04a9b5ab940d684aaaf04f2ba41
186 Risk Score

Malware Insights

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

The PDF contains numerous external links, flagged as a link farm, with one prominent URL pointing to 'kuzutuzo.ru'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or SEO spam. While no scripts were explicitly extracted, the PDF structure and URL patterns suggest it's designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://kuzutuzo.ru/wix?keyword=algebra+chapter+3+test+answers PDF link annotation
    • https://cdn.sqhk.co/soxesemu/behbHhe/99404261244.pdfIn PDF document text
    • https://cdn.sqhk.co/kefivaxepaj/GjbHPhh/man_booker_international_prize_2017.pdfIn PDF document text
    • http://acgmgroup.ru/fegijepumwj7d.pdfIn PDF document text
    • https://puzaloraren.weebly.com/uploads/1/3/4/5/134510283/kipuboli.pdfIn PDF document text
    • http://biomanix.best/texas_cdl_medical_cardeejgf.pdfIn PDF document text
    • http://weinmvc.net/diccionario_espaol_latinoamericanoqah99.pdfIn PDF document text
    • https://cdn.sqhk.co/nufesewepi/haAAxjg/business_development_plan_powerpoint.pdfIn PDF document text
    • http://trysucre.pro/78509598933tiykk.pdfIn PDF document text
    • http://reawont.online/894278935506dva2.pdfIn PDF document text
    • http://forkidsshop.online/27260724852w4tat.pdfIn PDF document text
    • https://cdn.sqhk.co/bexuxoxabim/hgkijgd/covid_infection_rate_by_state_per_100_000.pdfIn PDF document text
    • https://woliwaluv.weebly.com/uploads/1/3/4/6/134686062/zinikijifus_zokazijit.pdfIn PDF document text
    • https://cdn.sqhk.co/totafeta/aRidiir/instagram_app_login_issues.pdfIn PDF document text
    • http://zoneeuro.pro/naxajobx8gj.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cd9ed9ec-87d1-42be-9198-0b2de6c1db4d.filesusr.com/ugd/158fb9_2ca76b421df3424ea2dcb53563748c65.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/topipovikapari/fractions_decimals_and_percentages_worksheet_year_5.pdfIn PDF document text
    • https://f635e5d9-31b1-4f19-b758-7a623be10181.filesusr.com/ugd/6cf0f5_175e84beb21a4dc494d7590cf2261948.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/metubevozisul/akeley_wood_junior_school_inspection_report.pdfIn PDF document text
    • https://s3.amazonaws.com/bulalowisu/noxirawosiwotewafadowu.pdfIn PDF document text
    • https://s3.amazonaws.com/zuwosil/75620611063.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c527.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC527 3664 bytes
SHA-256: ac66f249644e4521da6a320da331c8969f02450b299b288ef2552f0e90563433
font_01_sfnt_off0000d133.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD133 5580 bytes
SHA-256: 3bbee1d95ecd4da00e91bbb709c8c320559bfc7936181b0e968f6abba376853a
font_02_sfnt_off0000e431.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE431 10232 bytes
SHA-256: f98ba8c121ec5b17b26b3dd9a58f702ea94a9d1854155acc6b65c67a76007bbf
font_03_sfnt_off00010780.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10780 16112 bytes
SHA-256: 62b559721a6967c5225c022894fd12f25c9dfad26b1ecba2375fced28481320e