Malicious PDF — malware analysis report

Static analysis result for SHA-256 23826b771e1416a1…

MALICIOUS

PDF

85.0 KB Created: 2021-09-18 23:46:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 88ffc37035257f0521b6a4a5d4f2e0ab SHA-1: 3c7affbbd8537440b270a59727a4b59ecd94b1ac SHA-256: 23826b771e1416a168dbcac800eb882b5da6feaebec05309543f1afe25fd5611
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The PDF also functions as a link farm, directing users to multiple external URLs hosted on potentially compromised or disposable domains. These links likely serve as lures for phishing or to download further malicious payloads, as indicated by the ClamAV detection and ML classifier flagging it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://bargiel.com.pl/ckfinder/userfiles/files/37499593256.pdf
    • http://portalpr-b2b.es/img/user//file/_0271411001631827732.pdf
    • https://szallas-karpatalja.net/upload/59209587519.pdf
    • https://elesud.it/img_pagine/file/laxiwasevatavedopolu.pdf
    • http://phdpecs.hu/userfiles/files/nebejifetupirarazisa.pdf
    • https://ichapps.peaceofworld.com/ichapps/ckeditor-ckfinder-integration/uploads/files/fakepuxoru.pdf
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/16139e7044e769---fudoloxolekujib.pdf
    • https://cplastik.eu/data/cms/file/94089001785.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/161304e93970a7---71970862768.pdf
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ee9ce6f38a---76337305150.pdf
    • http://cablexconsulting.com/Upload/file/46413749847.pdf
    • http://fine-cottage.ru/userfiles/file/481354341.pdf
    • https://pecintajp.com/contents/files/42257610779.pdf
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/161353a91268b4---xododevitofenir.pdf
    • http://tornyanggrace.com/upload/file/57472099563.pdf
    • http://2013.letnifestiwal.pl/ckfinder/userfiles/files/84369918388.pdf
    • http://naphotelbangkok.com/userfiles/files/70149105188.pdf
    • http://changwontour.kr/FileData/ckfinder/files/20210908_E94E993A7999F720.pdf
    • http://jiangsutravel.kr/userfiles/files/20210913_103413.pdf
    • http://www.llmhospital.com/www/js/ckfinder/userfiles/files/13586739755.pdf
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd940137f5---42659891647.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=rockstar+full+movie+download+torrent
    • 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_off0000df7e.bin
3c283740c113af4de127fba650f8dd0003a1f90be3528e7ace3cd9f571f922f2
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF7E 19796 bytes
font_01_sfnt_off0001130c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1130C 16792 bytes
font_02_sfnt_off00012b23.bin
0a202317a8e03514625e8ddc61712f78c6e0b1aed4a539fc8134a139a01ce538
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B23 11028 bytes