Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8e12e82caf7fd95…

MALICIOUS

PDF

84.2 KB Created: 2021-09-17 22:23:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b98dd76b1eb52e3fd592ecbecf4bca0d SHA-1: 88304d9851c0114d542e74f8c8231782ce58af33 SHA-256: b8e12e82caf7fd9593af18a4a67efa89ca62f26905e779aeb68d1f015ed74aec
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to potentially compromised websites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple external URIs and link farm heuristics confirms the document's purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://tw-jia.com/uploads/files/202109082012575329.pdf In PDF document text
    • https://ngusacdon.com/upload/files/38091350120.pdfIn PDF document text
    • https://nghiepvu.udicmanpower.vn/uploads/news_file/faxowesefusutew.pdfIn PDF document text
    • http://vnos.vn/app/webroot/uploads/files/folazomaseburesugobovem.pdfIn PDF document text
    • http://outspokenholland.com/userfiles/fckFile/20210903212549.pdfIn PDF document text
    • http://duszek-lasu.pl/userfiles/file/jijiforokilomikoj.pdfIn PDF document text
    • http://hyundai-dongdo.vn/images/files/77697520241.pdfIn PDF document text
    • https://mama-light.net/business_school/uploads/file/33425261742.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161424bb7eea81---44884027545.pdfIn PDF document text
    • http://dubilex.com/userfiles/files/65193701647.pdfIn PDF document text
    • http://ls12368.com/userfiles/file/25410138723.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/gafofapelel.pdfIn PDF document text
    • https://mystruggle.uk/indigo/ckfinder/userfiles/files/24327325353.pdfIn PDF document text
    • http://circuitoinsulargc.com/documentos/file/sevototuwuzowinali.pdfIn PDF document text
    • https://nepalonetours.com/userfiles/files/1295361241.pdfIn PDF document text
    • https://ivanda-commerce.hr/userfiles/file/30196953610.pdfIn PDF document text
    • https://sadhankendra.org/erc/media/96320671035.pdfIn PDF document text
    • http://balashixa.inhome360.ru/admin/ckfinder/userfiles/files/jusugebovixutalabepos.pdfIn PDF document text
    • http://eastindiaspray.com/suvra/eastindia_spray/files/31751416579.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad1e45c1cd---pevolib.pdfIn PDF document text
    • http://abworder.com/uploads/files/roxogojatuzajofejix.pdfIn PDF document text
    • https://searchlink.org/userfiles/file/jisagupimifabuv.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/4e741832ce89adf4ae54e40f6dbb7cb1/69989979042.pdfIn PDF document text
    • https://karapinarinsaat.net/userfiles/upload/file/45222072996.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=salvar+el+fuego+pdfPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD8F 10452 bytes
SHA-256: 3da8722b05fab052b8dee246ae4ec68caae05ee37d40d05eb08a6180286da364
font_01_sfnt_off0000f537.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF537 20548 bytes
SHA-256: be65cc952f56304dd970ee5fc65ed8626d77f48863723bdd102832220d70979d
font_02_sfnt_off000129de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1