Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4a5b2570959a52e…

MALICIOUS

PDF

89.5 KB Created: 2021-09-08 05:56:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 46598bb580dbfb1be8f2fb8554d1b9cf SHA-1: 1b988aa31ab4adc29e2998fbee62250e3af1a6ab SHA-256: b4a5b2570959a52e69b41778fd2614b98e09b52784eae421c0a8e155b3c6328c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://corianderedmonton.com/ckfinder/userfiles/files/73775429225.pdf In PDF document text
    • https://empezo.xyz/js/ckfinder/userfiles/files/zutul.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/gazelakuxawematotub.pdfIn PDF document text
    • https://minegociomiweb.com/userfiles/file/jelovuki.pdfIn PDF document text
    • http://caf-ljubljana.si/docs/2874811456.pdfIn PDF document text
    • https://horgaszvelem.hu/ckfinder/userfiles/files/8666654637.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8e851052d---19350547796.pdfIn PDF document text
    • https://almuhja.net/ckfinder/userfiles/files/kikofogonok.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba7dc312a95---83077378070.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/160865b10d1683---zivasox.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/hf1oukv939kch40kv2lndbc5a4/84259495931.pdfIn PDF document text
    • http://phutungquanghieu.com/app/webroot/files/ckfinder/files/76067537797.pdfIn PDF document text
    • http://laiyi-art.com/userfiles/file/jejurotezoludigi.pdfIn PDF document text
    • https://bloc-immo.com/images/80060225027.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160942280dfc6b---36145497425.pdfIn PDF document text
    • http://uralinteh.com/uploads/files/53490147450.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/eb5bead5e906c35390fef3afb2897d69/wuguse.pdfIn PDF document text
    • https://asiarsolutions.com/userfiles/file/lobimuro.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/ed15u4kca86varfhsheoi6f5ko/sezuwipafijafave.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210802074133.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a612e73dfbb---tasuvofesij.pdfIn PDF document text
    • http://stolizstekla.ru/userfiles/file/21861543044.pdfIn PDF document text
    • http://amindoost.ir/images/upload/files/roporavopov.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0920d6ef5b---zumokarobu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=list+of+gazetted+holidays+2019+in+delhi+government+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_off0000f4d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D7 11604 bytes
SHA-256: 6671600f9b83b502f5c4f739f39bfbea572be9a44bae4892e5ceee6c03dc92fe
font_01_sfnt_off0001102b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1102B 18432 bytes
SHA-256: f0a7ba0d2af2a9cae7207d9f8275d74cc8ba184f2c8ef7cc24069fd50658778b
font_02_sfnt_off00014027.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14027 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1