Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a931219e71d9710…

MALICIOUS

PDF

82.8 KB Created: 2021-09-01 18:29:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: b5a7b9037eadc0a0333d5ca19ca22901 SHA-1: c51192799eeffd86159bd8a4b7e6d93b2efc6e58 SHA-256: 5a931219e71d971072768e443ef156252e1583428911d33b027a53fcec119acb
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to numerous compromised WordPress uploads and other disposable hosting domains, likely intended to redirect users to malicious content or further stages of an attack. The presence of multiple external URIs and link farm heuristics strongly suggests a phishing or SEO poisoning campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://daming-school.com/userfiles/file/82369265888.pdf In PDF document text
    • http://esistore.be/userfiles/file/mobodudomoruliziser.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/160f62ab6b7cb8---tijumeponut.pdfIn PDF document text
    • http://kondicionery-ivanteevka.ru/upload_picture/file/19453838481.pdfIn PDF document text
    • http://shahnawazonline.com/uploads/files/36863605781.pdfIn PDF document text
    • http://rolmech-strzelno.pl/Upload/file/japagiromajonevaroj.pdfIn PDF document text
    • http://kamnitikamini.si/upload/files/39563048047.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d195abd2ed---41764601464.pdfIn PDF document text
    • http://esenkardeslerinsaat.com/resimlerfiles/4839701377.pdfIn PDF document text
    • http://kurier48.pl/files/userfiles/file/roxazitewozo.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/44775347591.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160e53acf5a7fb---tejinotamixil.pdfIn PDF document text
    • http://zvezda-rostov.ru/ckfinder/userfiles/files/wopegax.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/7baf2351f3207559ffd5433b55bf16a8/69058198546.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/fefafulibadopufa.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/409208db9c07d2147440ddc456bacd23/9489461192.pdfIn PDF document text
    • http://uhy-th.com/image/upload/files/36105378834.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1ae6cd975---gekolatoluderumeponirive.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/f7e42feb3299f4f8d846933412df2eff/5526901886.pdfIn PDF document text
    • https://iohrp.org/f_files/files/newaxezukivebedopefalav.pdfIn PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/8022611964.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/160785b7231fea---kilujuzejaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=another+word+for+contraceptionPDF 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_off0000d8be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f0d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D5 10572 bytes
SHA-256: 8245184c0abed2f1722893fc5842c2edd5d037a2d9ed8a9ca5915c0469061f94
font_02_sfnt_off000108f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108F4 19392 bytes
SHA-256: 6289beae811552bbf0867efb04a86b279cccbed5fb6f0b89e1165ff1d01f6147