Malicious PDF — malware analysis report

Static analysis result for SHA-256 71237e3df48d2f57…

MALICIOUS

PDF

80.8 KB Created: 2021-09-15 10:28:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 547e1909e97ceef44260d9dfa24a96f9 SHA-1: 7d9f6b150b8eb719fb2b6daaa8b0574a974a62ff SHA-256: 71237e3df48d2f574da309c2cf7b693e6b5cb3abdf3e15c3539b61c97402cd8e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm or redirection scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution through these links. No scripts were extracted, but the PDF structure and URL analysis are sufficient to infer a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/a119b7a0416e2ca1834b125f0f803af4/babanu.pdf In PDF document text
    • http://free-note.kr/files/fckeditor/file/1784868189613e090189bdd.pdfIn PDF document text
    • http://kartinatv.org/uploads/files/66269949210.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/8d5088a8930bd54b6893edc45c88b31f/89192555524.pdfIn PDF document text
    • http://bertrandetgastineaudesigners.fr/userfiles/file/gazonitot.pdfIn PDF document text
    • https://prokoncept.hu/admin/blogfck/image/file/wofetexisajafax.pdfIn PDF document text
    • https://k31szmq42-nu28.com/contents/files/suritokapiral.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614168895bf18---bapofijopibejupune.pdfIn PDF document text
    • http://bebaldebaran.eu/userfiles/files/1589059471.pdfIn PDF document text
    • http://sisparts.pl/zdjecia/fck/file/49718361168.pdfIn PDF document text
    • http://nghieuphong.com/upload/files/xaritifezajon.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/41f668b185a34d0bb73bd0c43ff277ed/81919150407.pdfIn PDF document text
    • https://unitedfightalliance.com/ckfinder/userfiles/files/rerewetodap.pdfIn PDF document text
    • https://vrindaindia.com/php/joseph/uploads/file/luvuw.pdfIn PDF document text
    • http://web5gstore.com/Files/files/nuvizixuzof.pdfIn PDF document text
    • https://ice-group.pl/userfiles/file/29770932893.pdfIn PDF document text
    • http://manu-transport.com/documents/file/32037786814.pdfIn PDF document text
    • http://sovaimm.it/userfiles/files/xakotuzivagaxebar.pdfIn PDF document text
    • http://leebyunghun.kr/new/upload/board/files/50850226331.pdfIn PDF document text
    • http://sangtaoad.com/uploads/userfiles/file/xigegogo.pdfIn PDF document text
    • http://naim.naparts.com/images/fck/file/8075356286.pdfIn PDF document text
    • http://steakclubhn.com/campannas/file/sivenufiv.pdfIn PDF document text
    • https://beaszemin.com/files/69720509440.pdfIn PDF document text
    • https://tutorsbureau.net/userfiles/file/951811871.pdfIn PDF document text
    • https://www.syria-report.com/sites/all/libraries/ckfinder/userfiles/files/42611781146.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=best+audio+cutter+and+joiner+for+androidPDF 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_off0000d582.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD582 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED94 17888 bytes
SHA-256: 9429888d1c41ac5fe1a04f2e31db1c6a424056aa8276b494f58a4be208395bce
font_02_sfnt_off00011ca5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA5 10708 bytes
SHA-256: 066eb386f02d9063a6ce586f9eb1993f62c1cd4428e10a7ed1808e56df990a83