Malicious PDF — malware analysis report

Static analysis result for SHA-256 42f31a9f9ec4b8e6…

MALICIOUS

PDF

92.0 KB Created: 2021-06-28 20:14:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 43f70613f9af243fcfc2d5ca44a75fb4 SHA-1: b3e405b48af1c6644b2f061ee13b00cc36715abd SHA-256: 42f31a9f9ec4b8e6648a7ce9267db6c2a1bc45b74dc0937c450ef8f738f4a9bb
156 Risk Score

Malware Insights

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

The PDF document was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to PDF files hosted on compromised WordPress sites, suggesting a link farm used for SEO poisoning or to lure users to malicious content. The presence of multiple distinct hosts and a large number of PDF links reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://aisef.org/uploads/userfiles/file/file/20738415311.pdf In PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/7db55c79a30500c9d98120e43426ac79/karoxexavugep.pdfIn PDF document text
    • https://alianzatours.com/imagenes/file/kasenawibutimenamol.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/pakufosurepuxugofeb.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/ritapetebal.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609fa8230b124---40569109588.pdfIn PDF document text
    • http://residencecarlofelice.com/userfiles/files/19515581573.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/4uigr6fmtiutbh1t05g0qn5mii/3154204014.pdfIn PDF document text
    • http://petra-dario.info/upload/datoteke/lovufalemode.pdfIn PDF document text
    • http://ciskmv.com/css/file/83014558251.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608bc641b7529---94042060784.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/75605958393.pdfIn PDF document text
    • http://macautemple.com/userfiles/file/masizafa.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ba162b2e9---47731748351.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/1a0313eee1aeaa09180ad7c5354df174/10358568427.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/b986ea9b3357c5a9905fb8f02050cd46/20853016761.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/p2f0fhs5o1267r0uk1ro4dbrj2/zekukisoxew.pdfIn PDF document text
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/467df3f30dcde604f73ca4e5cc8cc399/93293437552.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609094f36a3bf---wurevelerujeruvog.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/5ac96pl3m6ppsko760rt324ogh/talorepikunowedurinajof.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b43347a583---93447586159.pdfIn PDF document text
    • http://circuitvietnamcambodge.com/hinhanh/file/98684397763.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/xijedupazep.pdfIn PDF document text
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16090e057ad3a7---53147229226.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=acid+base+periodic+table+trendsPDF 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_off0001048d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1048D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011c9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C9F 17444 bytes
SHA-256: 1cc4b0309615aa6b9344cb8df7356f4a236ed64abf94ca82e4c69d8213d7e6f4
font_02_sfnt_off00014a71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A71 10628 bytes
SHA-256: e49ac2e5e8c109a02e54342ab36dca8b3f8a059a614e4fccdc17b9643b447a8b