Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4219647cb7f9474…

MALICIOUS

PDF

73.7 KB Created: 2021-09-25 17:44:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: bd21960e443885e3bffaaf7aa2b22303 SHA-1: 37c526ce30f64787f0bf7134be29f17666d6351c SHA-256: b4219647cb7f9474b620b619a6d5fbe8ed1652ebb949cc679337f49443a63fa3
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous embedded URLs that point to compromised websites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these links indicates an attempt to facilitate phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 https://krisoc.ru/uplcv?utm_term=zip+code+dela+paz+pasig+city PDF link annotation
    • https://samsungklimamodelleri.com/upload/ckfinder/files/37429069584.pdfIn PDF document text
    • https://mudrun.com/home/mud/public_html/ckfinder/userfiles/files/sujikeragetuxelokafuro.pdfIn PDF document text
    • http://gleb777.com/fck_upload/file/jofabalaxutozafodefa.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/jk17m3akuhbduf761hkdsj673o/51011391209.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144fb775268e---timopijekubim.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/959371929.pdfIn PDF document text
    • http://anquocrealty.com/uploads/image/files/geliwijolawafa.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/59206916230.pdfIn PDF document text
    • https://codecs.ro/images/file/ramugejokuv.pdfIn PDF document text
    • https://hagabb.ro/ckfinder/userfiles/files/51806626521.pdfIn PDF document text
    • http://www.pibmg.com.br/ckfinder/userfiles/files/files/66485035013.pdfIn PDF document text
    • http://stimatacasa.eu/userfiles/files/30290338087.pdfIn PDF document text
    • http://griesvoegwerken.nl/UserFiles/file/16258146561.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16131075c2b1d7---44639034806.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/zanul.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fa2ffbdfdf---55948144298.pdfIn PDF document text
    • http://www.sandipmallick.com/fckimages/file/16813596789.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161379df149392---61131019672.pdfIn PDF document text
    • https://dom4m.lv/userfiles/files/kuduguronomuxodaparaviso.pdfIn PDF document text
    • http://royal-pizza.eu/files/file/fupisilajakuwatig.pdfIn PDF document text
    • http://suvagcentr.ru/userfiles/files/76913246199.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/161459c773bc52---kozavu.pdfIn PDF document text
    • 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_off0000b92a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB92A 18284 bytes
SHA-256: 9d14a048d4ff94e0a26ac83c7a0a4c1c1ff82e23cdbe63df0f64fef20f02c324
font_01_sfnt_off0000e945.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE945 10624 bytes
SHA-256: 7e0b8c0db16ae708bac190805de7f7462aed0b0577df39369dda027b432c4e5e
font_02_sfnt_off00010193.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10193 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1