Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9bd21bfeb1eee22…

MALICIOUS

PDF

69.8 KB Created: 2021-09-24 13:15:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 6ab0bb1f8ffbff97a36643ddd7a15d96 SHA-1: c7d2138c3b7d4f0cd5682be76a970025d6bb3cb0 SHA-256: b9bd21bfeb1eee22f7f6b60fbb66412a60d3f516e0e939d347f44cc57591e000
134 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external URIs, indicating it is designed to redirect users to potentially malicious websites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests a link farm intended to obscure the true destination or distribute malware. The ML classifier and ClamAV detection further support its malicious nature, likely as a phishing or malware delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://xn--49st2et51duvk.com/upload/files/fakibisopagofowuxujom.pdf In PDF document text
    • https://lbk-ingatlan.hu/uploads/file/dubene.pdfIn PDF document text
    • https://mudraconsultancy.com/uploads/files/milubujafo.pdfIn PDF document text
    • http://otelm4b.ru/admin/ckfinder/userfiles/files/66114594328.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/31109385445.pdfIn PDF document text
    • http://dongphat.net/upload/files/xasogevizegopuxisovase.pdfIn PDF document text
    • http://pk-rowery.pl/user_pict/file/59432574132.pdfIn PDF document text
    • https://dp-engineers.com/admin/userfiles/file/65057444854.pdfIn PDF document text
    • https://cakesandcupcakes.net/userfiles/files/paxup.pdfIn PDF document text
    • https://shevian.com/images/file/24809642164.pdfIn PDF document text
    • http://stsmcc.org/www/js/ckfinder/userfiles/files/jewoxaxorega.pdfIn PDF document text
    • http://lifecare4all.com/upload/files/kuzetikatum.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16147deaa42a1d---8312944839.pdfIn PDF document text
    • http://thechitay.com/uploads/userfiles/file/wutevedetagurapit.pdfIn PDF document text
    • http://osingenieria.com/images/admin/file/29465543834.pdfIn PDF document text
    • http://copy-office.it/userfiles/file/77614418107.pdfIn PDF document text
    • http://ticketsperiodico.com/galeria/files/55715139649.pdfIn PDF document text
    • https://newtech-utm.pl/userfiles/file/38553890412.pdfIn PDF document text
    • http://fertilityupdates.com/userfiles/files/gamaruwogediw.pdfIn PDF document text
    • https://www.frontieregypt.com/sites/all/libraries/ckfinder/userfiles/files/nujurovi.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/famarifabiwutuputes.pdfIn PDF document text
    • http://xn--80aguejfegacgj0ad.xn--p1ai/pict/file/32081409249.pdfIn PDF document text
    • http://grupafurman.pl/!mag2011/userfiles/file/bukowisofav.pdfIn PDF document text
    • https://hotelcorona.ro/files/92219628043.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=waverley+cinema+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_off0000aff4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFF4 16484 bytes
SHA-256: 25fadcbb50da0c0f0f55a04585fb912fb2699dcf097165559d8ba335e206ca8c
font_01_sfnt_off0000da00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA00 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f217.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF217 10568 bytes
SHA-256: 7f94064d524f8ff82c64c67f837559eeead5f0b359ad026787e46e660c2218c2