Malicious PDF — malware analysis report

Static analysis result for SHA-256 8156d943e1c98d9d…

MALICIOUS

PDF

67.9 KB Created: 2021-09-25 02:13:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 333683b2e01124f07e63db07e5b1f58a SHA-1: 61504a0952cbdf81678692891d17e2df9a6d3fbc SHA-256: 8156d943e1c98d9d753ca482351a074d30c402c777e46b6330374c63d4e52343
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to lure users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://27derajat.com/assets/ckfinder/core/connector/php/uploads/files/35858467342.pdf In PDF document text
    • http://jinruily.com/UploadFile/file/20210916071850897.pdfIn PDF document text
    • https://equantumconsulting.com/files/files/61824648076.pdfIn PDF document text
    • https://burkina-businessschool.com/business_school/uploads/file/77058521782.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/2800d5e891d6033a2b34a0fd1961270b/zekim.pdfIn PDF document text
    • http://businessdevelopmentcenter.pl/uploads/userfiles/files/bulevikoganubabirovez.pdfIn PDF document text
    • http://www.como-grup.ro/fisiere/file/walajelunuxilenomide.pdfIn PDF document text
    • https://cailux.lu/userfiles/files/22692616438.pdfIn PDF document text
    • https://ideylia.fr/uploads/file/35658346426.pdfIn PDF document text
    • http://hypotekaprezamestnancov.sk/res/file/31797828947.pdfIn PDF document text
    • http://mindatpeace.us/uploads/files/18778410393.pdfIn PDF document text
    • http://studiomarazzi.eu/userfiles/files/xijarepunir.pdfIn PDF document text
    • https://tablouri.emilianchirila.ro/imagini/files/befuwesiduvuzujanixesinux.pdfIn PDF document text
    • http://yachtales.net/admin/userfiles/files/golovok.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/7ef43e13f901018c5f07d5e84348bd21/joxela.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1614b5e4324cb1---xiwumudenuxesozeveleniv.pdfIn PDF document text
    • https://kotata-zlin.cz/obr/clanky/file/61558172169.pdfIn PDF document text
    • https://hoya.mobioptika.hr/UserFiles/file/nevagulawowikokenitod.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/tli1tv0qt041b2skooenfrofqk/75229566043.pdfIn PDF document text
    • http://goref.ru/files/file/78215978256.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=adobe+photoshop+cs+8.0+crackPDF 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_off0000ab0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAB0A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c321.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC321 10980 bytes
SHA-256: 9ee4781846b33c9293b4089aa02443b593a87a8646a853162f40370a8cd4169f
font_02_sfnt_off0000dc92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC92 15240 bytes
SHA-256: c093fca29a4a7150f6450ce0996ced57321ccfab9891483ffe4e27a7f9fc6c1a