Malicious PDF — malware analysis report

Static analysis result for SHA-256 04a90b555b369576…

MALICIOUS

PDF

80.2 KB Created: 2021-08-07 18:18:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 6f92695269e9edd848aa32afc5dcb0d0 SHA-1: 76e9aeaad7ee70219912e66f8cd000d53dfef6b3 SHA-256: 04a90b555b3695760d1ef52848370f977eb7e18813ea5015d0e8e474b576ace4
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS upload directories. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests it is designed to redirect users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/ljt5ugmc4q7oq0hnp5fqn42cm0/54936056045.pdf In PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f8a11e96969---ditemadapon.pdfIn PDF document text
    • http://zonweringbelgie.nl/ckfinder/userfiles/files/kavusekozefujafudokil.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160804030e286b---gapileliku.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16085846debd46---jotasomifuxasovisutifu.pdfIn PDF document text
    • http://angarakshaksecurity.com/userfiles/file/48169708274.pdfIn PDF document text
    • https://xlspandoek.nl/userfiles/file/sanodisemukaw.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079336da61b1---56050678875.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/160775a7c08da4---sagitido.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160791a487352a---46257090144.pdfIn PDF document text
    • https://gotoko.com/cmsv2/upload/files/popudinowolomugizil.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/vulibuzanajamudero.pdfIn PDF document text
    • http://resetimpianti.it/reset/public/file/70601030944.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16091277852cb1---pupizogowa.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160bb75038b919---67735646744.pdfIn PDF document text
    • http://offerseir.com/basefile/offerseircom/files/5379293833.pdfIn PDF document text
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/katopabimalufijezivido.pdfIn PDF document text
    • http://www.serge-valentin.net/ckfinder/userfiles/files/39176626575.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/geldlp9hsjictqqbb5lrm1l8g3/43795871914.pdfIn PDF document text
    • https://chandrakantmusicacademy.org/ckfinder/userfiles/files/nexokof.pdfIn PDF document text
    • https://proxus.nl/file/16717547298.pdfIn PDF document text
    • https://energooptima.hu/upload/File/naderizerokubuzawe.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/160b388479d8cd---terenafusulezesawizarugok.pdfIn PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16084897eac3df---tegepikavilufog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=realtor+logo+pngPDF 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_off0000d710.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD710 17236 bytes
SHA-256: 2dbae39f5fd12dccd32af24c8eca1b938ffc880960287631576bd6db05266d57
font_01_sfnt_off000103e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E2 10212 bytes
SHA-256: ab9ecf32a69b642125053061fea20a81e9495406fd24b1ddef9eb45998e1deba
font_02_sfnt_off00011aee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1