Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4f30b6cbd0f0f57…

MALICIOUS

PDF

81.5 KB Created: 2021-09-10 08:53:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 6ad93733fe51d6256a19e7537fcb34ea SHA-1: afbd27749d087ef4594355942dd9c2eaf9cb1ba3 SHA-256: d4f30b6cbd0f0f57b3a0069768b8d3d849806fd2e44f8c83f11f62cfe70f10c2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, many pointing to compromised websites or disposable hosting, suggesting it functions as a link farm to redirect users to potentially malicious content. The presence of PDF-specific heuristics like 'PDF_URI' and 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://infrive.ru/uplcv?utm_term=loco+app+download+apk+old+version PDF link annotation
    • http://aescantabria.es/upload/fckeditor/file///90790247604.pdfIn PDF document text
    • https://bandotrading.com/uploads/file/sumelozitufekutugigutu.pdfIn PDF document text
    • http://hocomesun.com/upload/21146769199.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16134a00540452---69794519640.pdfIn PDF document text
    • http://fermobkorea.com/userfiles/file/20210905210144.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/17919800573.pdfIn PDF document text
    • http://sns-russia.ru/userfiles/file/10277979146.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161318742e46f7---muluvuvadojifezujupafi.pdfIn PDF document text
    • http://vetcasatenovo.it/userfiles/files/xavelaregajenalapikax.pdfIn PDF document text
    • https://rachelrom.com/rescontent/file/kexibiriso.pdfIn PDF document text
    • http://aapltd.net/userfiles/file/sudowalojifuzenenesejara.pdfIn PDF document text
    • http://dienlanhlongan.com/upload/files/17166467073.pdfIn PDF document text
    • https://ashasuchikala.com/ckfinder/userfiles/files/52978002948.pdfIn PDF document text
    • http://ugyvednok.hu/userfiles/file/40576908213.pdfIn PDF document text
    • https://zbmbudomont.pl/userfiles/file/bewan.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/9d62fb875adf608536cf41e78e50f7b5/47468205873.pdfIn PDF document text
    • https://stalbeckers.nl/userfiles/image/file/24225936677.pdfIn PDF document text
    • http://radissonhoteltraining.com/userfiles/file/nekuvejutoraki.pdfIn PDF document text
    • https://czus-lukasa.sk/userfiles/file/lifenuwewoxovewejemapozum.pdfIn PDF document text
    • https://ekoelprom.pl/public/images/editor/file/bifekigoxitemal.pdfIn PDF document text
    • http://evohome.pl/userfiles/file/61451037858.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_off0000d7f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7F3 10608 bytes
SHA-256: 54d571abf63e2c6b5b6ce4e157cc0fa6860efa903cb7042f2627ab5350686b30
font_01_sfnt_off0000f056.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF056 18644 bytes
SHA-256: c423fcce6f9a5aeb0643cb0cdb1b1d44b9d255bb9f467dbac09c771a3c6f610b
font_02_sfnt_off000120f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1