Malicious PDF — malware analysis report

Static analysis result for SHA-256 b83e186dde82d774…

MALICIOUS

PDF

72.7 KB Created: 2021-09-17 16:01:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 750f064886753a5e368348c7a7d49002 SHA-1: b4b5cdff99822c687217cd3bca4724700c9db726 SHA-256: b83e186dde82d774895df3f1f552b7e04f2a791bdd9882e48b367458d6becf4b
164 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, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 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.
  • 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://synerhu.ru/uplcv?utm_term=10+free+followers+on+instagram+trial
    • http://controlsystemco.com/cache/fck_files/file/39268681687.pdf
    • https://ever.dacola.com/upload/files/65982086056.pdf
    • http://festacreativita.org/userfiles/file/vawobuludekiverem.pdf
    • https://asiantms.com/ckfinder/userfiles/files/23947627321.pdf
    • http://pevak.info/UserFiles/File/wegixirixu.pdf
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/05d47816c6d34455550e08618b9314ba/xizimaz.pdf
    • http://namhungholdings.com/uploads/ckfinder/files/xusumonolomedavegekozok.pdf
    • https://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/d98ec3d66a5294aebaae1459a79f3edf/tavefokulexigiz.pdf
    • https://www.hemingway.bg/app/templates/js/ckfinder/userfiles/files/rixuzed.pdf
    • http://rydelko.pl/userfiles/file/lunabujesemebig.pdf
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/e46ba6d4e20990a2d3a6df6d1a2c803d/54868929171.pdf
    • https://volnynaklad.cz/data/file/fuligogi.pdf
    • http://szpital-sulecin.pl/images/fckfiles/file/zonejofuziremujimimi.pdf
    • http://thriftstorewebsites.com/flash/thriftstorewebsites.com/file/kubexipabu.pdf
    • http://flomojapan.com/upload/files/tirub.pdf
    • http://personnelstrategies.net/userfiles/file/41038475157.pdf
    • http://hzdsbg.com/uploadfile/1631557771.pdf
    • http://bbfrontedelmare.com/userfiles/files/11428512740.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/ajpto12enn4l2aklpc49f35p8e/zokudur.pdf
    • http://thuephotocopytaihanoi.com/upload/files/3580670461.pdf
    • http://casaledellasignora.it/userfiles/files/63084217306.pdf
    • http://ototavandosemesi.com/resimler/file/nutojejirexowuneru.pdf
    • https://apaman.ti-am.jp/js/ckfinder/userfiles/files/bunaputusizelixutukeso.pdf
    • http://globalfeedindustry.com/upload/files/keluxifagoziziju.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bc43.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBC43 16792 bytes
font_01_sfnt_off0000d455.bin
c3c4d4c25b6d03ab062ba83dd91c71daaa172d131b324b5838ea296544bf8c72
pdf-font-stream PDF embedded font (sfnt) at offset 0xD455 15864 bytes
font_02_sfnt_off0000fcaa.bin
0c38d6c8a1e224981c0396d44d8aac06b817d7e898f6d5987810fdf0e8cb670c
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCAA 10720 bytes