Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3b8793ac57d6307…

MALICIOUS

PDF

70.2 KB Created: 2021-09-07 13:11:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b12a7f4a021266fa08fa150a751a08c3 SHA-1: 9c5f0415bb64aa31d182c797f4b161ffe92f8c12 SHA-256: c3b8793ac57d6307c1f56047f84e8db400ae278de1af1b2aebc872f760287c85
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs that point to compromised WordPress sites, acting as a link farm. These links likely serve to obscure the ultimate destination and distribute malicious content or phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2105935335---digidek.pdf In PDF document text
    • http://sjar-tech.com/uploadfile/file///2021081323491323.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/saxotu.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607c33217ac18---kuvadikodoja.pdfIn PDF document text
    • http://bettynblue.com/upload/fck_img/20210802/file/66722585388.pdfIn PDF document text
    • http://cuuhoatudong.com/upload/files/zelegolagurobowupukorivo.pdfIn PDF document text
    • http://sunway.me/ROOT_PATHuploads/file/060026044664.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606e1db2c6e9d---bagoza.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/ec8e910013408b989d7d98f66bae0d11/semirenite.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/if7japfrllmq8q5l1v0m4kpm91/dujitodotivawu.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608cc15bc76c1---94841632244.pdfIn PDF document text
    • http://ipea.kr/userData/board/file/32622012634.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b63577b4220---28702086143.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/7dde6e25370325b076e862c88beb1bfb/xugikop.pdfIn PDF document text
    • http://nt-module.ru/ckfinder/userfiles/files/dufazamevelodogolu.pdfIn PDF document text
    • http://xn----8sbemnkjd7bfu.xn--p1ai/design/img/upload/file/sigedap.pdfIn PDF document text
    • https://basisnomor.com/contents//files/72337232292.pdfIn PDF document text
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/16d508c96e354376782164a22ae40e38/79204908304.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=mucosolvan+mini+ulotka+pdfPDF 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_off0000b268.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB268 10800 bytes
SHA-256: 1efada7d2fc8b384b91479e58174d7ec2e0794fe62c886b40cfd6c355a0a4492
font_01_sfnt_off0000cb52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB52 16136 bytes
SHA-256: a2a9335cc3a9a0944361e250bcdde2897788acd9baa5eba5907e09e398b66cdf
font_02_sfnt_off0000f3c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1