Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a4a30dccbdd9740…

MALICIOUS

PDF

81.4 KB Created: 2021-09-14 01:30:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 9a9f42051dadc756adb84bec5bfba47c SHA-1: ab214c235916f6125e84f992372a557b6b5d12ef SHA-256: 5a4a30dccbdd97403933d546d602708af041bbc5c1f1170dc254be179a1ff30c
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised websites and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple PDF-specific heuristics related to external URIs and link farms supports this conclusion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://tutorlookup.com/ckeditor/ckfinder/userfiles/files/givuxuvol.pdf In PDF document text
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/ruzevavogul.pdfIn PDF document text
    • http://abwcrainhwy.com/uploads/files/2683419838.pdfIn PDF document text
    • http://mmsmarin.com/imgimage/file/bubodu.pdfIn PDF document text
    • https://wroclaw-effatha.pl/grafiki/file/84044586316.pdfIn PDF document text
    • https://mygenius.ru/admin/ckfinder/userfiles/files/24215140581.pdfIn PDF document text
    • https://electroagro.es/pub/files/kizokoporeregixiroji.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/4c72ecc7828c25e9a7504c0997ed2ff0/pesikafa.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a1f1c9072c---43184566516.pdfIn PDF document text
    • http://zhouzhuanx.com/v15/Upload/file/202191455475082.pdfIn PDF document text
    • http://gymostrov.org/gymostrov/userfiles/file/lasawipa.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b978da48a1---pomexuxa.pdfIn PDF document text
    • http://harringtonassociateslaw.com/Test/JabzMedicalBillingService/userfiles/file/luvukuwi.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16132a0dc4cfc9---vajarasikupemux.pdfIn PDF document text
    • http://artio.pl/files/files/66878709723.pdfIn PDF document text
    • http://maynenkhipuma.vn/quangbasanpham/app/webroot/upload/image/files/34214657026.pdfIn PDF document text
    • https://associazionebriciole.it/public/file/23656858494.pdfIn PDF document text
    • http://prttour.ca/FileData/ckfinder/files/20210903_EC7381E7F88C6E3E.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/givegezabizu.pdfIn PDF document text
    • http://cathugo.de/res/wysiwyg/file/44442388148.pdfIn PDF document text
    • http://poornasreehomeoclinic.com/ckfinder/userfiles/files/rarobunexe.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1613a4e14afa50---feruwifuso.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/rcq1gg7g7nlsp4kueimrmema30/37941520587.pdfIn PDF document text
    • https://laatuwhuisweerstralen.nl/upload/file/sowubegalijopusu.pdfIn PDF document text
    • http://finalbrand.cz/upload/file/kotidibuzinag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=australias+deadliest+snakesPDF 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_off0000d9d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9D5 10296 bytes
SHA-256: e34349479d395352e09d5c12768b5f9677a69f9432971ea3569101cd7c75f407
font_01_sfnt_off0000f120.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF120 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010932.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10932 18104 bytes
SHA-256: 371c66c000ab1d03cd4f2bb11524a618127f3ce85c9ddac85b4137a6a13d8062