Malicious PDF — malware analysis report

Static analysis result for SHA-256 c81320e83d0f26a0…

MALICIOUS

PDF

95.2 KB Created: 2021-08-03 11:43:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 88233ed5b05e07bb82fea9934a527f6d SHA-1: 2fb08fb5124c756199f1dd8162f2a2bf6e14def4 SHA-256: c81320e83d0f26a06c022429927bb57417d035217e6f61568e8bfec5e0cb7b04
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The ML classifier and ClamAV detection strongly indicate this PDF is malicious. It contains numerous links pointing to compromised websites, suggesting a phishing or malware distribution scheme. The PDF is identified as a link farm, likely intended to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://pm-property.pl/userfiles/file/62322151304.pdf In PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609136450b01c---23710566737.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b574898e217---58853713040.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/504183ba31560c4ca5445af597ba1ab3/gugebabadodasulexaponamun.pdfIn PDF document text
    • https://globalazeri.az/wp-content/plugins/super-forms/uploads/php/files/p4774g057aj2sqe93477l78ag1/7446280348.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcfbd26e4e0---niwazigerudaf.pdfIn PDF document text
    • http://www.asap-recruitment.net/upload/file/maluven.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee31b215cc---gawogumed.pdfIn PDF document text
    • https://xn--fct8ml6mwue.tw/uploads/files/4645093576.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5bad1a4ed---62163964659.pdfIn PDF document text
    • https://cyberbirddog.com/userfiles/files/wumenajasasu.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/lcilcopfej9pj2i2qgok9h2dkb/71860319067.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/497227e10b873b2d040bd7cbb48d9d7b/64490068036.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160c7c31351ed9---91212176504.pdfIn PDF document text
    • http://slsnn.ru/content/files/97188723518.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/a3fb7f0faaf17729af65825496c7bc92/3206935672.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2aedd6ac7f---21814267349.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16108e076c85b4---91661535446.pdfIn PDF document text
    • https://zzhqhi.com/d/files/xupelaru.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=uff+da+meaning+norwegianPDF 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_off00010f9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F9D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000127af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127AF 18932 bytes
SHA-256: c628f637aa6eeb49255dbd10ef5fef7b047f73d518b2b0de97d7a34ad7b35e52
font_02_sfnt_off0001589c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1589C 10480 bytes
SHA-256: 11457dc7e3ea15455ca1ad7b62f690bf9d913ae56b8a28654a849bfdd7e5838c