Malicious PDF — malware analysis report

Static analysis result for SHA-256 309421bcda6f0255…

MALICIOUS

PDF

68.2 KB Created: 2021-10-01 00:30:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: cda256a4f26109c5405d6e40a00adc44 SHA-1: b3f5323de06322e1cbc91deb735c25ddd49742ca SHA-256: 309421bcda6f0255e43f84305bff80365f5b453f01b6f74a5bccfbe0cfa119a5
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and URL patterns suggest an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/f6vn9qvveh8eappoi75rdsslj8/33459079598.pdf In PDF document text
    • http://chinahk-ip.com/chinahk_ip/html/files/editor/file/zatoru.pdfIn PDF document text
    • https://yukkumpulgroup2.com/contents/files/70170096223.pdfIn PDF document text
    • https://badanie-wody.pl/galeria/file/49669605668.pdfIn PDF document text
    • https://am-system.eu/ckfinder/userfiles/files/japolivejawuv.pdfIn PDF document text
    • https://danielfelber.ch/userfiles/file/lizakotone.pdfIn PDF document text
    • http://studiopedrazzini.eu/userfiles/files/dopupupimipi.pdfIn PDF document text
    • http://dailymaydemtien.com/userfiles/files/85901160223.pdfIn PDF document text
    • http://alisawedding.com/upload/users/files/vawafenijoxudikegotidun.pdfIn PDF document text
    • http://ergakiland.ru/files/files/petivawo.pdfIn PDF document text
    • http://dataction.org/demo/dataction/media/83488543025.pdfIn PDF document text
    • http://mensagemcrista.com.br/ckfinder/userfiles/files/53295891404.pdfIn PDF document text
    • https://unovosti.tv/ckfinder/userfiles/files/68852265505.pdfIn PDF document text
    • http://sanga.asia/userData/board/file/fevadamujubobapegagonat.pdfIn PDF document text
    • http://hsound.ro/images/custom/file/rososuvisevi.pdfIn PDF document text
    • https://drhuanghair.com/uploads/files/202109260623519664.pdfIn PDF document text
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/hqtfak9micb5s6s2uja9ggt2gq/zozeguzumedab.pdfIn PDF document text
    • https://www.alugutader.fr/ckfinder/userfiles/files/guzes.pdfIn PDF document text
    • https://magnumattachments.com/ckfinder/userfiles/Files/jopomatosanufezirase.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613c792a5ff37---22353816419.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614964abbf461---17211980062.pdfIn PDF document text
    • http://pegasomeeting.medcoast.net/ckfinder/userfiles/files/27589894327.pdfIn PDF document text
    • http://dgjinhak.kr/DATA/upload/files/202109241219442544.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614c3caf3ab90---15076378570.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=knife+id+unturnedPDF 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://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_off0000b00a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB00A 9940 bytes
SHA-256: ea6abab16d211413ecb8a486fa0a89e9606605f8826355f8842e05b884d69db7
font_01_sfnt_off0000c613.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC613 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000de25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE25 14940 bytes
SHA-256: fe32103e4c6e9152b89284facf9e84b163642eba64b261b63b61c3ca8f0476a0