Malicious PDF — malware analysis report

Static analysis result for SHA-256 91c6706433103fef…

MALICIOUS

PDF

69.6 KB Created: 2021-10-02 17:56:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: da1a46a9278d720fa2e119006f955771 SHA-1: 2e91a6a6a4b550f5e561d70d2d2dc010a4832efd SHA-256: 91c6706433103fef2eafc5e7e6c2c8867d2b343cdd01e3c2786cfbd482ab19f5
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting it's part of a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is unreadable due to encoding issues, but the heuristics and URLs are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://cructi.ru/uplcv?utm_term=quickest+way+to+increase+snap+score
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161383299a3761---filuk.pdf
    • https://onutglen.com/caningest/images/file/58729081655.pdf
    • http://weingut-suppan.at/files/67352967738.pdf
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16158506b9c787---62116937684.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/krld91smetdnnh9t6c2ub9nti1/totezopujovuninitufufa.pdf
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140a3d5024a0---fodapufituzoz.pdf
    • http://bielle-srl.com/userfiles/files/kebulep.pdf
    • http://philipsphotographystudio.com/69161599995.pdf
    • https://tarsiman.ee/files/file/kimojobujexike.pdf
    • https://olgunbey.com/upload/ckfinder/files/wiwebinipu.pdf
    • http://vinabomi.com/uploads/userfiles/file/42786450062.pdf
    • http://rintoyo.com/userfiles/file/lugif.pdf
    • http://modernplating.com/userfiles/file/9277253334.pdf
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/161498eb8cc9ab---mitokijenudofu.pdf
    • http://suarezbeltran.com/aym_images/files/kosaxutizosozupigetew.pdf
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/16157000616abd---96801025513.pdf
    • https://www.savininkai.lt/ckfinder/userfiles/files/noroxavetekonavekefawiwo.pdf
    • http://mientrungland.net/uploads/image/files/zoxoragezujazusuluwir.pdf
    • http://fairfresh.net/assets/admin/ckeditorimage/files/xolulibusezulibur.pdf
    • http://qualityfirstservices.pro/testingsites/advantage_aviation/assets/media/file/losaxuwaxibodomelipe.pdf
    • https://egc.ecrom.work/syo/files/sawotafamevuji.pdf
    • http://sieuthicayxanh.vn/webroot/img/files/28784603195.pdf
    • http://polaryachts.com/res/wysiwyg/file/82218258921.pdf
    • http://szjg.hu/images/file/ginakevoge.pdf
    • http://uniskycn.com/userfiles/file/LianMeng202109220215289708.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b0a7.bin
4965b5c2c9cc8054c6003c0e041f4d74b4259439f3d0d5f909a7705997541833
pdf-font-stream PDF embedded font (sfnt) at offset 0xB0A7 10772 bytes
font_01_sfnt_off0000c9d9.bin
8950120dad9fc3c9e41df627bb56158563053664ba45cb5f0a73621d4149f115
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9D9 14744 bytes
font_02_sfnt_off0000eecb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEECB 16792 bytes