Malicious PDF — malware analysis report

Static analysis result for SHA-256 861c93e3bb670f2d…

MALICIOUS

PDF

100.3 KB Created: 2021-09-01 17:23:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 3d013d7a95a0bda1c115d356cf5191c2 SHA-1: 1faf43a7e1a80c3dbdd5a22190f891dfbd902eb9 SHA-256: 861c93e3bb670f2dc6a5e4c7c6c120b93305ae2959ed76b379db07637129a164
156 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded links suggest an attempt to redirect the user to malicious sites, potentially exploiting vulnerabilities in their browser or tricking them into downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9865

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://coverline.ro/userfiles/file/vabuniku.pdf In PDF document text
    • https://avgdesign.com/userfiles/file/28822617609.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090623ee065e---74989566349.pdfIn PDF document text
    • http://bioscipublisher.com/files/upfiles/file/70990225132.pdfIn PDF document text
    • http://jiuxingchaoshi.com/uploads/file/292200057258.pdfIn PDF document text
    • http://www.melloecastro.com/wp-content/plugins/formcraft/file-upload/server/content/files/160738cada978d---58096852631.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/f3804c941aa7a32a9c8328041d97741a/99709527131.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/837dc1c35b4476fd009cbf220dc6ac2c/24671471430.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fe05f09369---81534717514.pdfIn PDF document text
    • https://agatanorek.com/files/file/81299081975.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/f5108aa2d7d9c8adcc16e9b1100cfcfe/gaduvukexukevubutuluz.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d88a6f5ac67---20660776916.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e4693bc2f3---lekuzuzebefazepufuvi.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160906156d2695---meriwifojo.pdfIn PDF document text
    • http://shamayachts.com/upload/file/32651727523.pdfIn PDF document text
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/mgtn8ts51ncrp4184m7obnkurq/vujarudojivopibopeg.pdfIn PDF document text
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/452b1b8ce031a0464e03f50abc159ded/82668757904.pdfIn PDF document text
    • http://fotografieindex.nl/images/uploads/18136804244.pdfIn PDF document text
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/6e6f631276612cf128ac5cc797c2a61d/dijitulimuvopor.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612763eb8e362---legigu.pdfIn PDF document text
    • http://yaeram.com/userData/board/file/pebep.pdfIn PDF document text
    • http://plncse.hu/php_data/file/wikefodujuwomalowukekisen.pdfIn PDF document text
    • http://coeb.eu/userfiles/files/99669581236.pdfIn PDF document text
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/c063057ca7bd0244e520115d0085aa8a/79867080572.pdfIn PDF document text
    • http://udaybharat.in/ckfinder/userfiles/files/kiwutinowonawa.pdfIn PDF document text
    • http://kameleonhastanc.hu/files/file/61488522963.pdfIn PDF document text
    • http://herningbadintra.dk/app/webroot/upload/files/noxuvukos.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210509104305.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=average+yearly+temperature+in+japanPDF 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_off0001239a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1239A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013bb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BB1 10696 bytes
SHA-256: dc5bdc3ecc1a52f12e1243d7bf8a9db9e38d1891d77e412b9e10025c6ca5bd91
font_02_sfnt_off00015428.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15428 17996 bytes
SHA-256: 2bcca1a4f6351ffc95248f0d9b855aadd4ed92b3f61558a35a03ae471f4f2f2d