Malicious PDF — malware analysis report

Static analysis result for SHA-256 df8c9ec19ba6b231…

MALICIOUS

PDF

82.0 KB Created: 2021-08-03 08:38:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 91963205e389269203ab2eb5a7185c04 SHA-1: a28d232ea2ea1c861b6b9e6b6e1acb3a1e0c130e SHA-256: df8c9ec19ba6b231a7c0fad62d0873be47183123fc267a543a55266d0192233c
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous URLs, many of which are hosted on compromised CMS platforms or disposable domains. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the nature of the links as a non-clustered link farm on disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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 http://chretkinia.pl/userfiles/file/titazaluzazanipafewa.pdf In PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/344ff688be6c233a657f1f2f388def7e/49387443453.pdfIn PDF document text
    • http://saktigroup.in/uploads/wufalunu.pdfIn PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/9ukkoqn8olq4oid0p98kbuuhjt/93656327140.pdfIn PDF document text
    • http://xn--80aatg4aaaddkhfhbf3evf.xn--p1ai/ckfinder/userfiles/files/jeroladorudenadijat.pdfIn PDF document text
    • http://ventima.ru/userfiles/file/widoxubesidipopojosof.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/niderajamunelane.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c586536ee0e---86718219202.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/5388735653.pdfIn PDF document text
    • http://xn--k1akb4c.xn--p1ai/userfiles/file/89098500075.pdfIn PDF document text
    • http://www.oteliapelsin.ru/ckfinder/userfiles/files/85349310735.pdfIn PDF document text
    • https://baohohoanglong.com/userfiles/file/poman.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/39043709005.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/lt1fo9mhu388991p0oe0qpm3j7/87151344584.pdfIn PDF document text
    • http://ibb-online.ru/f/file/gomisigotitovifuled.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e414b1cdd1c---63532980317.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/51520133081.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/513aee1efbfbb70028ffed12e818553c/fimalavipexejelonitoju.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210504200640.pdfIn PDF document text
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/602f5c50953e4392a4e88c7b1945eab0/pewofamun.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/16085c3bd3be80---pasowobotowimufubepe.pdfIn PDF document text
    • https://mimpisiluman.com/contents//files/20869053566.pdfIn PDF document text
    • https://vivekanandbawwa.com/userfiles/file/73728401430.pdfIn PDF document text
    • https://landatur.com/files/galeria/files/bifuxuva.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086895bf10da---bozaxepo.pdfIn PDF document text
    • https://drproperty.in/userfiles/file/xuvixoxopomuxibefadukefa.pdfIn PDF document text
    • http://sztarmedia.hu/_user/file/wupilirinuzipug.pdfIn PDF document text
    • https://wildarium.com/ckfinder/userfiles/files/79744930881.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=pediatric+nutrition+handbook+6th+edition+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_off0000dcf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF3 11004 bytes
SHA-256: f089bd0bef7d9f6d7b5312f1b621cc3a910547e7d10217147ec5c49fa78bdf6a
font_01_sfnt_off0000f63e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF63E 16588 bytes
SHA-256: 584514231321667b34ba95c3c57bde2dbb276090ed2333bf3a23565e34c35085
font_02_sfnt_off00012151.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12151 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1