Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd70759fcfa5a5e3…

MALICIOUS

PDF

76.9 KB Created: 2021-09-16 17:50:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: fc958737aa9d5514121d97aa74cd918b SHA-1: dfbb07de32876f006a8f1a95806928f5cf0371cf SHA-256: cd70759fcfa5a5e3edc13c92ced79a33bfb6f36bed6b7f351548b409371ba293
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF functions as a link farm, directing users to multiple external URLs hosted on potentially compromised or disposable domains. These links likely serve as lures for phishing attacks or to download further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://synerhu.ru/uplcv?utm_term=xvideoservicethief+video+2018+apk+download+for+android+free+download PDF link annotation
    • http://ei-windykacja.pl/upload/file/28457110255.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135999584b93---jejujo.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210901_537C9108990AB0F1.pdfIn PDF document text
    • http://tuning-zone.eu/userfiles/file/gesupe.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b513e64864---78215490044.pdfIn PDF document text
    • https://iamtimeshare.com/userfiles/file/86173164824.pdfIn PDF document text
    • http://whitedwarf.ru/public/images/ckfinder/files/girezo.pdfIn PDF document text
    • https://safetyhanoi.com/userfiles/file/9250230593.pdfIn PDF document text
    • http://cncforginghammer.com/d/files/sufivufakalebad.pdfIn PDF document text
    • http://latiendasegura.com/contable_prueba/userfiles/file/8428776646.pdfIn PDF document text
    • https://nhatngudongkinh.com/upload/ckupload/files/29994026390.pdfIn PDF document text
    • http://happyhanool.com/ckupload/files/raseku.pdfIn PDF document text
    • https://maturana.cl/upload/file/2021207664.pdfIn PDF document text
    • http://tg-focus.ru/userfiles/files/vokegodobijekinejo.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f33aa3ae3a---zetisixonepakolabedixado.pdfIn PDF document text
    • http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/tutomegivoxagamabezurilaj.pdfIn PDF document text
    • http://ranjitabiswas.com/userfiles/files/40564014576.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/koloponogizolasirusi.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/94431709694.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/1241235bd137dde8c9d284301d3076d0/vuwasoduxakizoder.pdfIn PDF document text
    • https://jeneifogaszat.hu/cikkdata/files/lakirot.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_off0000c161.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC161 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d973.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD973 17832 bytes
SHA-256: de862c4f1a2477300e2c8517c69cecad8b93511c780b4827e62c05c4f6fbc778
font_02_sfnt_off000107e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107E2 11472 bytes
SHA-256: 17f25b292091fd35d0e9a1106f6711121ebf2ea7cbc289c29f28b7252bcf870c