Malicious PDF — malware analysis report

Static analysis result for SHA-256 d23c2cd67c968564…

MALICIOUS

PDF

68.0 KB Created: 2021-09-27 19:54:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 21b785420385c8c92f0383451f60b1fd SHA-1: f7f51e7bc2af7661ec1c0b65655502bf2dd12d3d SHA-256: d23c2cd67c968564dedebf1fbbb0f8c309ef1dba65db6e78cbac364fb2989233
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to disposable hosting, characteristic of a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://irlanc.ru/uplcv?utm_term=what+is+trend+in+fashion PDF link annotation
    • https://nusantarabet4d1.com/contents/files/41646388370.pdfIn PDF document text
    • http://bsp-plovdiv.org/ckfinder/userfiles/files/wimodasujajidafujonetepo.pdfIn PDF document text
    • https://inprovitecuador.com/ckfinder/userfiles/files/dataroropa.pdfIn PDF document text
    • http://hongdanhaudio.com/luutru/files/64217092727.pdfIn PDF document text
    • http://crystal-lamp.ru/uploads/files/tiwaje.pdfIn PDF document text
    • https://cfi-registration.amyhalter.com/buzzboxgift/img/userfiles/files/90200365053.pdfIn PDF document text
    • http://zamokugrofa.sk/admin/fckeditor/file/luzozowagovuzawuzaz.pdfIn PDF document text
    • https://lombardpruszkow.pl/local/userfiles/file/kiburumutinawonujetitoze.pdfIn PDF document text
    • http://ikcem.org/userfiles/file///90492476783.pdfIn PDF document text
    • http://pscworld.eu/ckfinder/userfiles/files/zowanojawixu.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/wumejopenimu.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/kapotiwuzuzulazawo.pdfIn PDF document text
    • http://www.bandungmesin.com/file/33225727519.pdfIn PDF document text
    • http://ghefoot.com/fckeditor_userfiles/file/zigikodijazutetigomase.pdfIn PDF document text
    • http://banglenhospital.com/UserFiles/File/duwisosujijapujaxavetokix.pdfIn PDF document text
    • https://bloomeng.com/uploads/99953232224.pdfIn PDF document text
    • http://xn----7sbakn3aoflleitf3m6a.xn--p1ai/userfiles/file/84474239471.pdfIn PDF document text
    • http://danangsculpture.com/uploads/image/files/wexokewokisu.pdfIn PDF document text
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/f54dc655f2dd6ce9b438425e797358fc/16578250822.pdfIn PDF document text
    • https://greenfins-thailand.org/uploads/file/vubonakegosotikagekezasu.pdfIn PDF document text
    • http://spalovnachemolak.sk/userfiles/file/55730989857.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_off0000abfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xABFE 15444 bytes
SHA-256: 9ed68e8babf4c9a49430963ce77b9f13f062206884701dc68a5fc1f4e4e24b80
font_01_sfnt_off0000d34f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD34F 10400 bytes
SHA-256: 18123d937758aeffc76e460902030eba1278f4beda24aa4817858c4afc594abf
font_02_sfnt_off0000ead8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1