Malicious PDF — malware analysis report

Static analysis result for SHA-256 824c6ccd03e3584e…

MALICIOUS

PDF

78.7 KB Created: 2021-09-20 08:29:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 99d67617b521c6cc68af521df3d3c33c SHA-1: 253e3e638e631d49b72783791062a87391ca9913 SHA-256: 824c6ccd03e3584ed2c006b43addaba942e47bf48c9e95434681e027845e6ff1
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The PDF also features a large number of external URIs, many of which point to potentially disposable domains, suggesting a link farm or redirection scheme to host malicious content. The presence of embedded JavaScript and numerous external links indicates an attempt to lure the user into visiting malicious sites or executing further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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
  • 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 http://vngo-cc.vn/cooker/public/files/43841087731.pdf In PDF document text
    • https://sandp-engineering.com/ckfinder/userfiles/files/fojidomukurev.pdfIn PDF document text
    • https://europacreativaeuskadi.eu/files/galeria/files/46968913383.pdfIn PDF document text
    • https://charterfori.ir/basefile/charterforiir/files/redovonovo.pdfIn PDF document text
    • https://dangeloremodeling.com/nbloom/fckuploads/file/32382854885.pdfIn PDF document text
    • http://serextion2006.com/js/upload/files/xogidebigefam.pdfIn PDF document text
    • http://debrecen.varosom.hu/userfiles/files/52172375638.pdfIn PDF document text
    • https://flardochform.se/userfiles/file/69629208481.pdfIn PDF document text
    • http://kayapalinakliyat.net/file/xivotigarawoge.pdfIn PDF document text
    • http://www.medic-pneumolog.ro/fisiere/file/53067260288.pdfIn PDF document text
    • http://himalayakebab.irafbrothers.com/shipinc/userfiles/files/12031078420.pdfIn PDF document text
    • https://albertoangel.sinecsas.com/ckfinder/userfiles/files/30661445553.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613567026deac---bufapesew.pdfIn PDF document text
    • http://kondicionery-dolgoprudny.ru/upload_picture/file/74784271399.pdfIn PDF document text
    • https://searchkar.com/ci/userfiles/files/88736612037.pdfIn PDF document text
    • https://cvssteelex.com/ckfinder/userfiles/files/40234069994.pdfIn PDF document text
    • http://goraku-sangyo.com/userfiles/file/fajutafugavepapumerev.pdfIn PDF document text
    • https://medsplus.us/admin/images/file/92786293413.pdfIn PDF document text
    • http://tayles.com/uploaded/bujoselubepuw.pdfIn PDF document text
    • http://rsti.biz/files/fck/file/papuburujok.pdfIn PDF document text
    • https://solturism.ro/images/file/86708263149.pdfIn PDF document text
    • http://rm-centr.ru/uploads/file/84352141658.pdfIn PDF document text
    • http://www.sas.edu.mn/ckfinder/userfiles/files/lixadulidi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=android+lint+tutorialPDF 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_off0000d1e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1E0 10024 bytes
SHA-256: 30005dd5bf706be743c2c48d812e1a8b4416e59682853a30b35dfa9688b5590b
font_01_sfnt_off0000e830.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE830 17400 bytes
SHA-256: 1f246e8244be4fbf1a1cf47f96b7393e76e083ee8f87ca71a80a185f00924257
font_02_sfnt_off000115a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115A3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1