Malicious PDF — malware analysis report

Static analysis result for SHA-256 13820378870e54c7…

MALICIOUS

PDF

88.9 KB Created: 2021-06-11 16:29:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: cf3db308ed92717fc0974e6d1a7ad0a7 SHA-1: 2b382473b84ca441d1f7655a151b03eb2c6b4e10 SHA-256: 13820378870e54c749c0533e8d7aa417541eef8bf15d9208e4705689da040ca8
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://medvor.ru/uplcv?utm_term=copy+and+paste+invisible+letter PDF link annotation
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a86fa5a7c6---23364029266.pdfIn PDF document text
    • http://originalcheck.it/public/img_admin/file/%5C/jowakamurawipobusage.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/b99bf32c756f1f4b36e12e09814d29e9/7228290304.pdfIn PDF document text
    • http://agendaalzheimer.org/files/galeria/files/juxixejo.pdfIn PDF document text
    • https://apoiotelecom.com/imagens/img_fckeditor/file/73621399581.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bdb5caa7e65---vubepatezikatelunizamoz.pdfIn PDF document text
    • https://freedomhypnosisnyc.com/wp-content/plugins/super-forms/uploads/php/files/285157172e5a4e16a19653167fb93b91/sisetaxazupesebim.pdfIn PDF document text
    • http://albatrossmrn.com/konadnew/userfiles/file/ganidofofobutuguzi.pdfIn PDF document text
    • https://repare-ton-smartphone.com/userfiles/file/tozajokox.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/d23290307f3c05ae60a541c64b043850/vovesisitevutugaxamox.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/k1lo7jh16bbstlt334b5f94s6o/nedotabavomexisosiwuku.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/792148bf416bfc4daa7d7110ce5fa6d6/70334638077.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/c9dd263f0fa1c16d3ce4bde48986a71d/lokusagogiseva.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076a3b4883d2---sasosoli.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1df6f0ec49---kejopejademubajutot.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9992390ef0---lunusotegov.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/d958fadac7c4d4114018c618048e26c3/dituporidazumijazi.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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000edb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB8 4344 bytes
SHA-256: 326dd4a03de746780dc05581d612ae5317b26c75b957f6150d3be70b0df87091
font_01_sfnt_off0000fc19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC19 5160 bytes
SHA-256: 61b683555c3f9c66c4244b145167e5e17ca6d59957288333073ed4b1bea496c4
font_02_sfnt_off00010daf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DAF 2044 bytes
SHA-256: babc028b02039550d9c0d01550e5e57a0c76770a29f74e542451f310a98bca3e
font_03_sfnt_off0001172e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1172E 12156 bytes
SHA-256: 3491d35fc95281bfd99d76f4a56c66a7d5d609edbc3fffaa886f8139660ad169
font_04_sfnt_off00014006.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14006 16340 bytes
SHA-256: 85a2634d7fe58a4860f7ed5e2881ed0c7412a347e31116798f8d6c4dce18b827