Malicious PDF — malware analysis report

Static analysis result for SHA-256 4815bd4fdb5e5bbf…

MALICIOUS

PDF

73.8 KB Created: 2021-09-19 01:18:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c94e270d9b52d9fc620549fcf375fde7 SHA-1: 52ebaba73bdc06269d5947b8401ee749af51b7e1 SHA-256: 4815bd4fdb5e5bbf3b282a46cfc61dec9fce42e6f401a3116edbdda12fd0a5cf
156 Risk Score

Malware Insights

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

This PDF sample was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress upload storage and other disposable hosting. The primary purpose appears to be directing users to external, potentially malicious sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://coretry.ru/uplcv?utm_term=fm+instagram+apk PDF link annotation
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16140e33eb1292---vurisaxuxok.pdfIn PDF document text
    • http://hitmet.slektenkaas.com/bilder/file/fezunikezajilitoxez.pdfIn PDF document text
    • http://eros-arena.de/eros/userfiles/file/gatinegorajivikusolok.pdfIn PDF document text
    • http://siamsankyo.com/Uploads/file/sedemezukutewomoni.pdfIn PDF document text
    • http://elistaprezentow.pl/userfiles/file/74824487211.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/gimolibosanubezosejoxipi.pdfIn PDF document text
    • http://mnarch.it/userfiles/files/11444782962.pdfIn PDF document text
    • http://rfaaa.com/UploadFile/file/20210906074906443.pdfIn PDF document text
    • http://tdbakademi.org/userfiles/files/81813624253.pdfIn PDF document text
    • http://vpsystem.com/files/fck/9408706404.pdfIn PDF document text
    • http://zajazd-broadway.pl/galeria/file/pomokunogib.pdfIn PDF document text
    • https://aep-tc.com/cache/fck_files/file/98895909645.pdfIn PDF document text
    • https://fullmagicweekend.com/ckfinder/userfiles/files/demuxixaxefupatej.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/pekosoj.pdfIn PDF document text
    • https://ceylanotel.com/firma/files/lefoborekelapajuwatokaru.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/1ade8d6fe48027bef7dc3c9f711a6e5c/32995967283.pdfIn PDF document text
    • http://aquarium-kochi.com/app/webroot/ckfinder/userfiles/files/87362347670.pdfIn PDF document text
    • https://transport.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/66467158249.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/161300e0a51d6b---pubejokawagofumezofa.pdfIn PDF document text
    • https://ichibaninfotech.com/ckfinder/userfiles/files/lugekaman.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-13/20210913015639756164.pdfIn PDF document text
    • http://stamforgtechnologies.com/uploads/17582271307.pdfIn PDF document text
    • https://cosanuesa.com/componentes/editor/ckfinder/userfiles/files/dozinixop.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://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_off0000bf37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF37 10364 bytes
SHA-256: 7bb3bdb974cc70e00e32f33d18cffa17398d82842103de10cdf51be46c000f20
font_01_sfnt_off0000d68c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD68C 16800 bytes
SHA-256: 21632258620622130b1b1160c13504bfd0b911a064cd61137b2cc89f46020333
font_02_sfnt_off000101e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1