Malicious PDF — malware analysis report

Static analysis result for SHA-256 4631283d20010f3c…

MALICIOUS

PDF

74.5 KB Created: 2021-07-14 05:29:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a010ccedb844cf301dd171a6fff3ffb2 SHA-1: eb94c60aab87e4016d9baa3cc5bfc893459faf9e SHA-256: 4631283d20010f3c8f07822d691749ff0ad8c23cf1045f3bee0c958da6ffb418
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs, many of which point to websites hosted on compromised CMS platforms or disposable hosting, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://chcial.ru/uplcv?utm_term=an+introduction+to+sequential+monte+carlo+pdf PDF link annotation
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608d54453fbdc---rudowo.pdfIn PDF document text
    • http://imi.vc/upload/files/pemonavek.pdfIn PDF document text
    • http://agiusfuneraldirectors.com/files/file/nurekinoxogilamegujet.pdfIn PDF document text
    • https://soudurelauziere.com/upload/editor/file/92107822688.pdfIn PDF document text
    • http://brenna-ski.pl/userfiles/file/sonufesubap.pdfIn PDF document text
    • https://mimpishio2bet.com/contents//files/rekovizabozet.pdfIn PDF document text
    • http://polymer-optix.de/userfiles/file/61292482791.pdfIn PDF document text
    • https://red-adlay.com/upload/files/tenafezudux.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/xagosodofulakojisukosod.pdfIn PDF document text
    • https://afra24.com/basefile/afra24/files/kowonafofizigijigamuj.pdfIn PDF document text
    • http://sowa-architekci.pl/userfiles/files/fofufutepugowimumog.pdfIn PDF document text
    • http://rebizplus.com/userfiles/file/mosoxakadusavawarepofusaf.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/xosovezasinutotuvamafer.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606fdcc48a224---popusiz.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606ccb4024182---10912595284.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160be4d9b6e959---paxawanitu.pdfIn PDF document text
    • https://anandamsanyal.com/userfiles/file/gejuxufupibopetemise.pdfIn PDF document text
    • https://iominneapolis.com/wp-content/plugins/super-forms/uploads/php/files/6691d3a898a2cb8f981764a11792632e/94359561404.pdfIn PDF document text
    • https://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/eb910c54f8a5fb686218dd21e6dc6db9/74764119253.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/45482250613.pdfIn PDF document text
    • http://liavanhaeringen.nl/userfiles/files/milumup.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_off0000bf76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF76 16840 bytes
SHA-256: 45f55c44b50f3d80f105aff943e6a51575e3ceec0c29e869127944927a97d470
font_01_sfnt_off0000eb22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB22 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010339.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10339 11008 bytes
SHA-256: 76e4051243838e624a621996b778408beea70732d801a060219caee8ab6ccfb1