Malicious PDF — malware analysis report

Static analysis result for SHA-256 8569a9a311dd8748…

MALICIOUS

PDF

88.4 KB Created: 2021-07-18 05:42:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 6f45c62b42e58c66d759613603660eb6 SHA-1: 57ed28fd404a2a5ded7c6aaaa4422a8a64d2a670 SHA-256: 8569a9a311dd8748a164b64f2edbd752c7d5da5461a789060f177cbbbb58ddac
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external PDFs hosted on compromised WordPress sites and disposable domains, indicating a link farm or SEO spamming operation. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to distribute further malware or phishing content through these redirected links. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded URLs.

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://dermaktif.com/imgup/file/28620020047.pdf In PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/gk244ljdtcuenotqksdfcjghh7/nulevipimipavadewawufemi.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/mususetemexuwoxuturitubuz.pdfIn PDF document text
    • http://flemisterbauldingfamily.com/clients/8/82/82a21d9598fc66f9117a8fb7222c8fd0/File/zagubuseripirobexu.pdfIn PDF document text
    • https://minutesnap.com/wp-content/plugins/super-forms/uploads/php/files/e783f27b64999058d4c382913618a492/40787027950.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/3758903261.pdfIn PDF document text
    • https://strechybenesov.cz/content/46821706029.pdfIn PDF document text
    • http://ahrestygz.com/userfiles/files/20210607_051232.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/dipuduleji.pdfIn PDF document text
    • http://rialta.ie/userfiles/files/11343118015.pdfIn PDF document text
    • http://randalljroutson.com/clients/44711/File/97637086525.pdfIn PDF document text
    • http://slsnn.ru/content/file/74883120411.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9780e485d---javukapagixomoraleka.pdfIn PDF document text
    • http://wisdomtours.net/upload/file/jabarifikivulibunarigobew.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607b33bd1eb2e---14080989907.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/60757e33d4af84cf48de9c7dbd4eee50/zinikis.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609cd47655237---papefam.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/kesujawol.pdfIn PDF document text
    • https://colakcivi.com/userfiles/file/matijibasiluditawigodexip.pdfIn PDF document text
    • http://gloucesterclassof81.com/clients/23558/File/pupuvutavuxemisunutasu.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160928e1f3ecfe---jabav.pdfIn PDF document text
    • http://popnmusic.fr/userfiles/file/pujajiwixegizarenivar.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/a47551c030d4f176fca14357e26bfc52/81933633983.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/90d398c6b4e157607464e252dadc7736/sizaxiron.pdfIn PDF document text
    • http://gramercygrand.ru/files/file/beroni.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=how+to+convert+multiple+files+to+pdf+at+oncePDF 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_off0000f515.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF515 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010d2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D2C 11024 bytes
SHA-256: 4304feec13a555e7f1ce103b37793e7a7a4ce4752e6d3d5b40a0f31c5c08cd5a
font_02_sfnt_off000126cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126CB 17280 bytes
SHA-256: 5579fc2b3d7463ca40684cc4797f1a72091b44618ca120651a2711873843a7cb