Malicious PDF — malware analysis report

Static analysis result for SHA-256 8258bba5fc9e4538…

MALICIOUS

PDF

71.5 KB Created: 2021-06-17 19:49:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: f6bb1d6af597d148e1174ea23e6127ee SHA-1: 643d67f00afecbdf360c6a09af35d4b22270b7c7 SHA-256: 8258bba5fc9e4538a9854fced27ee80b4caf3d3a6d83e956765fa3ffbc63aac8
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, suggesting it might be a generated document used to disguise malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://screen.by/images/file/25332063637.pdf In PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/efl4a3is19s30uh3nr12cmucn4/56041095554.pdfIn PDF document text
    • https://sjalikave.hu/pictures/file/21024369078.pdfIn PDF document text
    • http://sns.hu/_user/file/kiwadeguvulariwudop.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/f210f75810dc0bc9118e1d126a7ac60d/25602729089.pdfIn PDF document text
    • http://studiobaliva.eu/userfiles/files/jutimomuvobagogofizadu.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ee5766732a---46603010087.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/tvo8jbmgpiq23logshtvcgnld1/nomajinotefakupigutovod.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16077c10967dc9---pazugamejipire.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/31c562bc44a23411db12f604dc83d51e/16661376989.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fd9d9604fb---sozivimel.pdfIn PDF document text
    • http://ruresept.ru/files/file/45026421518.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607832b87ca9d---demugapimiso.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160caa9eda1f0f---vowavazosojuzizalotu.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/58413218497.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/149fab8ec075575b319c311008a3ed86/budikerakati.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=batman+prey+read+onlinePDF link annotation
    • 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_off0000dae2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAE2 5076 bytes
SHA-256: 4df69a26d64831f2bc52d9285058430a792b951e1f3e37e96722da5a04fe918e
font_01_sfnt_off0000ec18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC18 10940 bytes
SHA-256: 122aed293ff0843889ee5ed1944db3110274aa56c829cd1638fc5449c7a5cfcc