Malicious PDF — malware analysis report

Static analysis result for SHA-256 5051d0626dc0390a…

MALICIOUS

PDF

76.6 KB Created: 2021-09-18 03:20:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 03f2429db7c428f6afc70ef0c1952f66 SHA-1: 1200b74628e5d423bf00d84c6971f9d88f74e30e SHA-256: 5051d0626dc0390ad39b70f414630892c0052c132c9478ca70c2226b51bf2ed2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this. No scripts were extracted, but the overall structure and URL patterns indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://ketchas.ru/uplcv?utm_term=lucky+patcher+official+apk+ios PDF link annotation
    • https://mediaskills.rs/files/kolajotodawoxoti.pdfIn PDF document text
    • http://www.elstar.ru/uploads/files/66954382817.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132d02e75012---jupimoz.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/07pg1faqjmv3e0oe4t1judcdj4/23029578501.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/3p07mfhsl33dmolnv5n1akmb78/25900174517.pdfIn PDF document text
    • http://take114.kr/FileData/ckfinder/files/20210911_C48536AF8009D57C.pdfIn PDF document text
    • http://frankifoto.com/uploads/pages/files/30333106903.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/rn7vce5k9crhkcdd16m5nbpbm7/95922352873.pdfIn PDF document text
    • http://boston.pl/fck_pliki/file/8065667568.pdfIn PDF document text
    • https://searches.onlineconvey.com/userfiles/file/texugefesokakamugeronukiw.pdfIn PDF document text
    • http://hoteldazegliotorino.com/userfiles/files/muregijonujopa.pdfIn PDF document text
    • http://abarappresentanze.it/userfiles/files/82730386619.pdfIn PDF document text
    • https://wietsevoermans.nl/ckfinder/userfiles/files/56796255134.pdfIn PDF document text
    • http://xn--zb0by3yusal20ak5lcidnwigi.com/ckfinder/userfiles/files/1631774642.pdfIn PDF document text
    • http://cmtsport.com/pliki/zokomid.pdfIn PDF document text
    • http://e5tbr.alruaa.com/ckeditor-ckfinder-integration/uploads/files/sazudisemuzupevetefa.pdfIn PDF document text
    • https://mvmdigital.gr/files/files/bukibojusisodanaku.pdfIn PDF document text
    • http://maility.pl/_ADRESuserfiles/file/puwexuxajajajibilide.pdfIn PDF document text
    • http://livilgirls.com/files/gizaj.pdfIn PDF document text
    • https://neksav.com/upload/ckfinder/files/21982815308.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/95668825656.pdfIn PDF document text
    • https://www.twibiotech.com/plugin/ce1/ckfinder/userfiles/files/30963769192.pdfIn PDF document text
    • https://www.afoa.org.ar/backend/ckfinder/userfiles/files/8723818335.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_off0000c700.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC700 17468 bytes
SHA-256: 514409df8132d5a8446acbd7019f04ad302feb315a6ada2cde1bef3429b6e3ed
font_01_sfnt_off0000f3e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010bff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BFF 10736 bytes
SHA-256: 6b6cacb6800725d0b00b5f54c6c3e35e475f99d5a02ac1250b351561c95d8e38