Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a2ef51924a6ed8f…

MALICIOUS

PDF

74.6 KB Created: 2021-09-08 23:20:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f22689416c764731ba71e5d38e9bf808 SHA-1: fdffacdfd2ae2bcfd7d1ce75a46c242bfe3c3624 SHA-256: 5a2ef51924a6ed8ff4a236e35445f60d79e70e9ac7ff21403ee1c6adc80d5d9e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous external URLs, with one identified as a link farm on disposable hosting, suggesting a phishing or redirection scheme. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards an attack pattern involving the exploitation of PDF vulnerabilities or social engineering to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://chungangroup.com/uploads/files/202109050720432727.pdf In PDF document text
    • http://horvathortho.hu/tmp/vowewojetajaluniminan.pdfIn PDF document text
    • http://xn--d1achljw0b.xn--p1ai/content/upload/20169371313.pdfIn PDF document text
    • http://luatsugiadinhviet.com/upload/ck/files/5657682835.pdfIn PDF document text
    • https://madspot.dk/ckfinder/userfiles/files/wewaruzi.pdfIn PDF document text
    • http://aodaiminhhanh.com/app/webroot/uploads/files/46270886387.pdfIn PDF document text
    • http://twilaw.com/files/files/33978507247.pdfIn PDF document text
    • http://fzcce.com/aimgs/uload/files/forojixesewazuxara.pdfIn PDF document text
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/29875055282.pdfIn PDF document text
    • https://bilegt.mn/userfiles/files/67870534635.pdfIn PDF document text
    • http://kerekagy.hu/UserFiles/file/25778092531.pdfIn PDF document text
    • https://jucariicopilasi.ro/app/webroot/files/userfiles/files/norulapoxarelup.pdfIn PDF document text
    • https://lionkingbali.com/uploads/file/25407249514.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132d1b8d2b3d---deniluzugosurujikulowe.pdfIn PDF document text
    • http://tetobox-budapest.hu/uploads/files/85238093325.pdfIn PDF document text
    • http://popmetre.com/news/files/43267556146.pdfIn PDF document text
    • http://qualityspices.in/ckuploads/files/medavegobikamugowefa.pdfIn PDF document text
    • https://zilalcooling.com/other_files/File/wuxobijuloxi.pdfIn PDF document text
    • http://phannhan.vn/files/usersfiles/files/mipixapel.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/14510406363.pdfIn PDF document text
    • http://multi-accueil.fr/ressource/site-image/files/gezivifox.pdfIn PDF document text
    • http://gibkrakow.pl/uploads/files/wanadejijitanad.pdfIn PDF document text
    • http://barrospizzadb.com/uploads/files/90507208017.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=carl+orff+carmina+burana+pdfPDF 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_off0000c131.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC131 10656 bytes
SHA-256: 4395036de566586c749ba8ef080c25415136f09fe7351c23770b98f9e54c60a6
font_01_sfnt_off0000d943.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD943 16864 bytes
SHA-256: 6254d64eea09e215edd06c38abc1971c935c9f0dac030958b8688a7c658f2097
font_02_sfnt_off000104a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1