Malicious PDF — malware analysis report

Static analysis result for SHA-256 aac6c8db6bfb0397…

MALICIOUS

PDF

92.6 KB Created: 2021-10-09 05:58:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e07268a90a899f5d35fe8a42e52e12ab SHA-1: 025189a46f8b22bad720bbe8be3bd5d411713df7 SHA-256: aac6c8db6bfb03973fb4c3fa5800f8c154043f0e8b6191f9075de780becc4d0b
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of compromised CMS upload links suggests a tactic to host malicious files on seemingly legitimate but compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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
  • 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.
  • 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=sperm+donor+natural+conception PDF link annotation
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be6111e254---46225951930.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161395e3743c70---kusigixarukuxevu.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16160f63581315---demogo.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/pixivosoxorowixuwex.pdfIn PDF document text
    • http://www.otevrenysklep.cz/ckfinder/userfiles/files/40742780067.pdfIn PDF document text
    • https://izometal.net/mm/file/74600980842.pdfIn PDF document text
    • https://oxfordjsr.com/userfiles/file/taranotezed.pdfIn PDF document text
    • http://ducthanggroup.com/webroot/img/files/wofafoxud.pdfIn PDF document text
    • https://panegovernance.com/ourprojects/chowki/UserFiles/file/39637945251.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613148720c17f---sovenanebugerotosunuvejos.pdfIn PDF document text
    • https://ijfbacknumber.com/editor_up/jetenuvosa.pdfIn PDF document text
    • https://hw-power.com/uploads/ckfiles/files/615eb4fff080a.pdfIn PDF document text
    • https://rux-thai.com/ckfinder/userfiles/files/77479631855.pdfIn PDF document text
    • http://ylphs.com/ckfinder/userfiles/files/zebesez.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/gabs15b4356446didsjdc36us8/sikogofiseporizijezub.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/simete.pdfIn PDF document text
    • http://greenhousehotel.vn/uploads/image/files/4657957795.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/161468289d1b83---90470860273.pdfIn PDF document text
    • http://chinalabware.net/d/files/37747250374.pdfIn PDF document text
    • 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_off0000fecb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFECB 10684 bytes
SHA-256: af1c30d00da0b6ed7cd4c1dc75351b86a5949f542946ba79d5609571591bad91
font_01_sfnt_off0001173c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1173C 20996 bytes
SHA-256: 28219d5e9e8307c2ec0d61de082d53e19dbcae417b798fa7d2d257a96448a126
font_02_sfnt_off00014d94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1