Malicious PDF — malware analysis report

Static analysis result for SHA-256 53fce057737acddc…

MALICIOUS

PDF

81.3 KB Created: 2021-08-27 07:27:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 599b673a2e6a9311500c7d5566abdef6 SHA-1: 675eb6dac2da2b473fd7b3244761ecf08377074e SHA-256: 53fce057737acddc4041cac698b77ef69d48c94bc33eca8fa95131fa061bf192
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, suggesting a link farm used for distributing malicious content. 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 0.9942

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://pistant.ru/uplcv?utm_term=a+princess+in+theory+book PDF link annotation
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16071891b0af94---92073073350.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/luvetevezosi.pdfIn PDF document text
    • https://hotelexpert.ro/uploads/files/79734439121.pdfIn PDF document text
    • https://kit-veron.my/ckfinder/userfiles/files/zikulibeneduluwukuro.pdfIn PDF document text
    • http://kapli74.ru/upload_picture/81930141616.pdfIn PDF document text
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/94e079f6c8686c72a31a538113b18823/24325469782.pdfIn PDF document text
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/d34bf37051b16318a4436d7c867ac994/jolesibanufepogego.pdfIn PDF document text
    • http://happysmilecard.com/uploads/files/61308676238.pdfIn PDF document text
    • http://protok.pro/upload/files/jitanu.pdfIn PDF document text
    • http://jncs.kr/page_data/file/20210610060723.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c58a995ca0a---9814364123.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160725a5fb3ffa---93968623607.pdfIn PDF document text
    • http://okulsanmalatya.com/imgup/file/vatowajub.pdfIn PDF document text
    • http://shinyoungvalve.com/userData/board/file/lexulag.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160fade06be55b---2909728647.pdfIn PDF document text
    • https://thediamangroup.com/_images/files/67612883283.pdfIn PDF document text
    • http://akademia-jedenastka.pl/zdjecia/fck/file/1612198999.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160f509c401775---xukunobina.pdfIn PDF document text
    • http://edwindijk.nl/home/edijk/domains/edwindijk.nl/public_html/uploads/file/modufatulilarufemajib.pdfIn PDF document text
    • http://www.jfac.kr/ckfinder/userfiles/files/texorodolikadoweduve.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/scfqn4vj9fahg7a6fpc5qp2jcq/kavibedibikuxofivelonigar.pdfIn PDF document text
    • http://ladyqueen.it/userfiles/files/39171478819.pdfIn PDF document text
    • http://a-daily.jp/app/webroot/contents_img/files/15720247461.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/v635o10rp8luslravla6h0o636/95607220203.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160da6fab8017c---majifuzorunamozinixevodi.pdfIn PDF document text
    • http://britishcytology.org.uk/ckfinder/userfiles/files/71364039358.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_off0000dbee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBEE 16536 bytes
SHA-256: e941e88218a83c7b84fe72943b765057e7f00cc848804797efadfb2dd49a7cbd
font_01_sfnt_off000106d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106D6 10592 bytes
SHA-256: 06f07125bff0700d51dbc4a68d7c14c3377e6ad843043c01ccb53119703dd3d8
font_02_sfnt_off00011ece.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ECE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1