Malicious PDF — malware analysis report

Static analysis result for SHA-256 21c9934b909f4aad…

MALICIOUS

PDF

84.8 KB Created: 2021-09-16 01:10:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a44d7931ed10cdc41c41e6704680fa86 SHA-1: 715e7c4cc03b360d195d07fb8627a1ceb6359c82 SHA-256: 21c9934b909f4aadc3c2fcd69fe551fd41bf0645a4b43d3d5038423e130a0f55
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to PDF files hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these external links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://pixomot.ru/uplcv?utm_term=libros+de+contabilidad+de+costos+pdf+gratis PDF link annotation
    • http://thuaphatlailongthanh.vn/upload/contentFile/minhchau/file/rugopupenokibagofopo.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d726a8b148---80020579768.pdfIn PDF document text
    • https://artistaone.co/userfiles/files/43949010214.pdfIn PDF document text
    • https://isosklo.cz/uploads/94942010061.pdfIn PDF document text
    • https://felicityokolo.com/file/11952476098.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16132b1f5ebc08---surer.pdfIn PDF document text
    • http://envigest.cz/upload/file/lopuruzixoborawateti.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f058dad6c6---lijenerafizajavo.pdfIn PDF document text
    • https://hiroyoung.com/data/files/nojexisala.pdfIn PDF document text
    • http://www.cddfct.com/up_files/file/jibinedizejogoxolav.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/d8btt6i3gtkv6os4sscdapq8uv/87433068617.pdfIn PDF document text
    • https://kme.pl/global/app/webroot/uploads/file/16308610982405.pdfIn PDF document text
    • http://millecolori.it/images/file/vodetip.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2b5e98062---18586655387.pdfIn PDF document text
    • http://capesociety.ca/uploads/files/81734485472.pdfIn PDF document text
    • http://urotunisia.com/uploads/FCK_files/file/pudagaxix.pdfIn PDF document text
    • http://poexali.org/static/image/_u/system/files/72017003611.pdfIn PDF document text
    • https://dbhattacharjee.com/ckfinder/userfiles/files/1378522307.pdfIn PDF document text
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/87803487010.pdfIn PDF document text
    • http://seowonbattery.com/files/fckeditor/file/203934626861332591d6a50.pdfIn PDF document text
    • https://sporyolu.com/resimler/files/tukorusiradojo.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_off0000e389.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE389 19504 bytes
SHA-256: 96b7b5934344072eb69d7bbba322532eaafeffd6dcc1756e780cdc073b50d164
font_01_sfnt_off0001148f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1148F 10892 bytes
SHA-256: f29713a4c72039054f7b0aeeeff44e322e902627c3374e892f3713f6364c2ab5
font_02_sfnt_off00012d75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D75 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1