Malicious PDF — malware analysis report

Static analysis result for SHA-256 31fd3d716d7f2c2b…

MALICIOUS

PDF

78.7 KB Created: 2021-09-06 15:28:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ab4a9215d68638b196e7f356c0db1ad4 SHA-1: f8ee8597290e83b7637ff96ddab6647d26dd8d3a SHA-256: 31fd3d716d7f2c2b0e54b41824cad0d93fea53c613a6e20670244ed25158ac7f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous links, many pointing to compromised CMS upload storage and disposable hosting, forming a link farm. The presence of external URIs and the nature of the links suggest a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 https://irlanc.ru/uplcv?utm_term=learning+gnu+emacs+pdf+github PDF link annotation
    • http://bezagsecurity.cz/userfiles/71813057797.pdfIn PDF document text
    • http://www.buildingmalawi.com/images/uploaded/documents/zirinaje.pdfIn PDF document text
    • https://naoshima-habitant.com/3747420934.pdfIn PDF document text
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/xojaz.pdfIn PDF document text
    • http://fecoil.com/userfiles/file/gopevijigutowobogeraf.pdfIn PDF document text
    • http://greenmodels.ru/uploads/files/jubumogenuduxaponomimeb.pdfIn PDF document text
    • http://bhk-aindling.de/userfiles/files/vovikedova.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16095aaac1658a---vovabusalekudibozegirixu.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16096143969aba---21008982462.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/52qngkvepak8o5esiq3nr9i90f/mofoxe.pdfIn PDF document text
    • http://chapaconoticias.com/assets/ckfinder/core/connector/php/uploads/files/35953226974.pdfIn PDF document text
    • https://golf-tout-terrain.com/publish/page/file/87637881300.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/jorixunalupipazezizu.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/rupivirogowuzuxelevituliw.pdfIn PDF document text
    • https://novahealthclinic.ca/userfiles/file/vokixuvujojafawepiteva.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ee00976ed9f---zowege.pdfIn PDF document text
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/sgtmfg76s3qjqsn4r1ig5itcb2/xelagepegumad.pdfIn PDF document text
    • http://logisticsnetworks.net/ckfinder/userfiles/files/satebakejulemalifej.pdfIn PDF document text
    • https://behbehaniprojects.com/uploads/files/babozasa.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a22562b5b90---82887246204.pdfIn PDF document text
    • https://atcotourismtravel.com/userfiles/file/4327747729.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca2fae43ddc---21128883228.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160909d6344174---56779725553.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/54418dc2f99e47f550ef13cc0fb08963/70163003175.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093daa740649---70200220549.pdfIn PDF document text
    • http://france-ex.com/images/blog//file/3067168362.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_off0000cea1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEA1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6B3 17476 bytes
SHA-256: 3b15ad85ca209dc72a072916c6486a34094f8d6a6dee7e112c095d8dd25cb3e7
font_02_sfnt_off00011424.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11424 11096 bytes
SHA-256: 6419b1c54bc75108fd2b88778bccb5d617a164cf78ef2737a521193bd778222e