Malicious PDF — malware analysis report

Static analysis result for SHA-256 51c782848e0c41e3…

MALICIOUS

PDF

73.0 KB Created: 2021-06-09 10:45:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: caf385e664a60478f515e13ea7392519 SHA-1: 8c0e1d8921ff7939d055b93ab631f244fcf3a6a9 SHA-256: 51c782848e0c41e35f361fe3c158af98b5a62fecae9fef1686074e1db270747b
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan distribution attempt. It contains numerous external links, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the overall structure point towards an attempt to exploit users through deceptive links, likely as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://laborke.ru/uplcv?utm_term=fake+joystick+apk PDF link annotation
    • http://4grd.com/cmsimages/file/63995479329.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e6bbe3b6e1---87448846666.pdfIn PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/bab2df05f3573f98855841fc741803c1/87990783688.pdfIn PDF document text
    • https://advik.net/userfiles/file/87446469736.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16074564c24939---toxiguxomatud.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072ecf94fb70---fikewadudix.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a2fa9363b44---vexotisotap.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/9vcjvhc991hq48u92dltn042n7/pudefupamesi.pdfIn PDF document text
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/8720bab3bc5b21e7b756b7fce9f393b0/87919059988.pdfIn PDF document text
    • http://clinicaveterinariailmarzocco.it/userfiles/files/pilitokexefuraguwebijav.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/fomezi.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/tbu49v8d3lqq56ifhk3ip7otlk/9858064619.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/b1b4ed6267511d6bf98ee91e45038038/50873089564.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea7c52e08a---guninutakuwonolulemo.pdfIn PDF document text
    • https://www.prestigeautobody.com.au/wp-content/plugins/super-forms/uploads/php/files/318cb2802135165f7c73dcb66aaffc6f/6345271636.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_off0000e06e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE06E 4996 bytes
SHA-256: 59b7dd88a4874f73dcfced074fa74c2754283551d8c204ba83dced26cb194c49
font_01_sfnt_off0000f19d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF19D 11164 bytes
SHA-256: a0b8140a15cd8d3dcd2381af792cc6d30e36a991088679325f3b55b6568d65e8