Malicious PDF — malware analysis report

Static analysis result for SHA-256 405c308c8a8f60c0…

MALICIOUS

PDF

87.1 KB Created: 2021-09-15 18:55:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: cb4b6ee158b75a25b3e068430276f759 SHA-1: d1cf9705e28223532a5bb0e418a9bed0b9a5a86f SHA-256: 405c308c8a8f60c065d6c5afd3cd9aee136b488a7eb654bee7e8d8984f169521
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple links to external PDF files hosted on various domains, some of which are flagged as link farms on disposable hosting. The presence of embedded JavaScript and the nature of the external links suggest an attempt to download and execute a secondary payload or redirect the user to a malicious site. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://gcr.goldcrownresort.com/magazine_files/files/nadibi.pdf In PDF document text
    • https://rowanmkt.com/Uploads/ckfinder/userfiles/files/82439447823.pdfIn PDF document text
    • http://stellarp.com/userfiles/files/94965974495.pdfIn PDF document text
    • https://taperagi.com/contents/files/gokamuxob.pdfIn PDF document text
    • http://hodinovysoused.cz/upload/file/lavasojowixasowinulomi.pdfIn PDF document text
    • http://sensor4you.com/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/82975626636.pdfIn PDF document text
    • https://aadhaarretail.com/administrator/imagetemp/file/86753373901.pdfIn PDF document text
    • http://fpole.ru/sadm_files/36675805661.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf79496e27---sogituwolap.pdfIn PDF document text
    • http://bindashnews.com/userfiles/file/nidakusajowibilulexozu.pdfIn PDF document text
    • https://vinacomvietnam.vn/uploads/news_file/94021663326.pdfIn PDF document text
    • https://dlt-nkp.com/fileupload/file/xusexusegafozujakukog.pdfIn PDF document text
    • https://geniodelweb.com/file/3907517120.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/7b5c5804256fad42c8d5bf6f83e595d2/nenojapagaserojuz.pdfIn PDF document text
    • https://relans-nn.ru/images/docs/file/temowusu.pdfIn PDF document text
    • http://hoaiduc.edu.vn/ckfinder/userfiles/files/gojuninekol.pdfIn PDF document text
    • https://transport.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/4602046613.pdfIn PDF document text
    • http://all-vehicle.net/js/upload/files/nuzerojuzud.pdfIn PDF document text
    • https://netcsemege.elelmiszer-hazhozszallitas.hu/ckfinder/userfiles/files/davirabiwepoduwoxiko.pdfIn PDF document text
    • http://clinicaveterinariacittadivignola.com/userfiles/files/23234717811.pdfIn PDF document text
    • http://boekenwinkelindex.nl/images/uploads/17909217075.pdfIn PDF document text
    • http://theexplorerthai.com/userfiles/files/97524039434.pdfIn PDF document text
    • https://vialivonica.eu/userfiles/files/69029867585.pdfIn PDF document text
    • http://clerus.hu/files/file/rivenabinopejulewomob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=invisible+dot+text+copy+and+pastePDF 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_off0000efe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE4 17876 bytes
SHA-256: 98422a50c73605e30c0dd8b2c4b73ce30f6a55161390f3f2da273332085545bc
font_01_sfnt_off00011de3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DE3 10780 bytes
SHA-256: 4371aeba8fa94f850261bac2756c5013e78e952bfa3ddc44190f84a40dd6fe77
font_02_sfnt_off000136ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1