Malicious PDF — malware analysis report

Static analysis result for SHA-256 522f7d0268ef7685…

MALICIOUS

PDF

107.2 KB Created: 2021-05-28 06:36:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 229424e15b6621df9a545d32c6a853f5 SHA-1: 025eb13c668997a80f803c489efce11a34adfc96 SHA-256: 522f7d0268ef7685b652670e5ce27ff40aeab33d81d087413c1db09db20b2e8d
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of embedded URLs and the nature of the heuristics indicate a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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://krisoc.ru/uplcv?utm_term=is+ethereum+mining+still+profitable PDF link annotation
    • http://didocrosby.com/imagenes/file/tefukuzodidi.pdfIn PDF document text
    • http://www.microsinusectomi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084e25da74e5---8971962252.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/iv0o1qrbkhete8k7lhemoi3klh/relitasuti.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad16b601115---1326083004.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609346fa61b6c---pupudexogoxegil.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16071b8086aea6---rewemokuxanewo.pdfIn PDF document text
    • http://blissrenewbeauty.com/newerac2c/userfiles/file/xivegarokodeg.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7cf6f14b5a---bujodobidugoxemekilole.pdfIn PDF document text
    • https://spacio.hk/attachment/file/bizobomekusazevunolep.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/e93bb13251d8e90b6e49e4128eaaf643/vozageruriwebokaba.pdfIn PDF document text
    • https://allcreaturesinc.com/files/files/8347124368.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072c4a5df246---97571145756.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/iqmg0mj64sabiai0l8f3b6gsc1/3185930001.pdfIn PDF document text
    • http://learningkey.org/userfiles/826699027.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/fa3801b7b19d1eb680f9b904a5ab0203/latimesopexajuvakij.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/snpfon2pu6sku4tcuc8k4o2njh/saxofonuremowaxilowo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00016567.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16567 5392 bytes
SHA-256: 2c9d7124cbc91843362e50b469bedd1e19a2183e82d444fd1ac372f7822f08a0
font_01_sfnt_off0001778e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1778E 11944 bytes
SHA-256: 94618fd3b84f4cee79272844a5d4c6cdc2638563c87e7618ed2a4036d8d051ea