Malicious PDF — malware analysis report

Static analysis result for SHA-256 eeff8c825a39dc82…

MALICIOUS

PDF

72.9 KB Created: 2021-09-14 05:25:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: aa56b2c5dac029a17f11d3f9aabfa435 SHA-1: f8badcae4b0af54dbd3de8fc4ef46255678e40fe SHA-256: eeff8c825a39dc82fb1238018dd05077ccd0e4210e7b7843754d511156a72f30
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous external URLs, several of which point to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://navoloki.mebel18.com/uploads/files/nuxawunidapowizejeratun.pdf In PDF document text
    • http://onlinevay.com/upload/files/5261691517.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16135134b61137---fazotonavudofejane.pdfIn PDF document text
    • http://sithome.com/upfiles/file/20210912103702.pdfIn PDF document text
    • https://pinyardim.com/calisma2/files/uploads/zimaw.pdfIn PDF document text
    • https://wroclaw-effatha.pl/grafiki/file/7545132975.pdfIn PDF document text
    • http://tangiahoang.vn/Images_upload/files/12246909471.pdfIn PDF document text
    • https://medbioplast.com/klucharnet/images/file/14208478283.pdfIn PDF document text
    • http://epicridesnepal.com/files/23924406283.pdfIn PDF document text
    • http://domoticasociale.it/immaginiNewsletter/file/gujilixiputajesowuva.pdfIn PDF document text
    • http://pokeocncafe.com/uploads/files/91916506814.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16131651a1010e---2862666921.pdfIn PDF document text
    • https://bbu.vn/Images_upload/files/87782806279.pdfIn PDF document text
    • https://laptopserwis.com/app/webroot/media/files/sumiregokekivugixuxek.pdfIn PDF document text
    • https://evpersoneli.net/ev-personeli/file/697155967.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1613174cb5fb09---38534543413.pdfIn PDF document text
    • http://pk.mo/userfiles/file/sesojenumomub.pdfIn PDF document text
    • https://chungcungoaigiao.vnpec.xyz/uploads/files/28612700285.pdfIn PDF document text
    • http://ulv-fogger.es/d/files/bufuduvubovut.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139c5a128e27---34735748248.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/35166196247.pdfIn PDF document text
    • https://mgs-on-track.com/uploads/misc/files/6020344822.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=f+scale+guitar+tabPDF 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_off0000bb48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB48 10400 bytes
SHA-256: 1e40d0e5df5ebbc2724ff12b349832278d99d827930ca4464f61c52b8e40854f
font_01_sfnt_off0000d2f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eb0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB0B 16624 bytes
SHA-256: 2d5b1f35d98fb3de42a8826f9c7df4cff78c82ec294b3532eeac43326e5a9781