Malicious PDF — malware analysis report

Static analysis result for SHA-256 8337ef951ad11993…

MALICIOUS

PDF

75.1 KB Created: 2021-09-20 16:03:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cf061973ec4c1dcf29a73ba82aab53b6 SHA-1: 43a1b227fc3b0a2cecb4fe097b8b6e0da0976ee0 SHA-256: 8337ef951ad11993f1d4ab2b59086b8f246b8367b595d4945e3b498be3ea5127
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS upload storage 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 0.9973

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://catamma.ru/uplcv?utm_term=stalker+player+for+android
    • http://shrlie.com/upload_fck/file/2021-9-12/20210912215758316819.pdf
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/4892c6fe0e3477e0723477510c8c8fcb/xaxolejukinetajawet.pdf
    • http://bike-aholic.com/UserFiles/file/72974683827.pdf
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/161390dc992177---46097708474.pdf
    • http://www.centralperdana.com/file/xadilejonazefaxenepajag.pdf
    • http://cesvil.it/filesUploads/file/69279885217.pdf
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/7142364b7c93bac08a511a47cce9e7f7/89668057052.pdf
    • https://3eyamaichi.com/upload/ckfinder_temp/files/20210912192320.pdf
    • https://bruceleevideos.org/images/file/rizenevewokuko.pdf
    • http://abbwingslynnhaven.com/uploads/files/ledivimarajovi.pdf
    • https://panegovernance.com/ourprojects/chowki/UserFiles/file/48429273628.pdf
    • http://yugang360.com/upload_fck/file/2021-9-4/20210904163838178107.pdf
    • https://childprotectionindia.com/lexcyberia/userfiles/files/82287998192.pdf
    • http://falconltd.pl/cache/file/3957338250.pdf
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/pempjvm8sn1c0gqc0t8actnh7n/pagebazeduwefokejiz.pdf
    • http://davidhammerstein.org/userfiles/file/41994877821.pdf
    • https://lawtutors.co.uk/js/ckfinder/userfiles/files/83456204470.pdf
    • http://tcsklife.com/filespath/files/20210914112108.pdf
    • https://tiemhoamo.tiemhoahaibara.com/data/dulieu/files/pudiwajixaxorevepum.pdf
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139ae956ef29---risasujaxibakegoxofopowe.pdf
    • https://renault-service.com/userfiles/34610508413.pdf
    • http://yachtales.net/admin/userfiles/files/92135026396.pdf
    • http://ppfi-online.com/userfiles/file/jeborazolinez.pdf
    • https://www.educazionesessuale-scuola.ch/ck/ckfinder/userfiles/files/37171291621.pdf
    • http://needychild.org/ckfinder/userfiles/files/widiguf.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_off0000bf79.bin
9bb0b3263be604cf530174d305ffa2a78fd26a87b8ab538aa5aa2742b439c233
pdf-font-stream PDF embedded font (sfnt) at offset 0xBF79 17852 bytes
font_01_sfnt_off0000ee03.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE03 16792 bytes
font_02_sfnt_off0001061a.bin
8954987e36aa70aa27cd95ee1b4071fcc0952635563bebbf712c53759b4611ed
pdf-font-stream PDF embedded font (sfnt) at offset 0x1061A 10604 bytes