Malicious PDF — malware analysis report

Static analysis result for SHA-256 555c109676e687e3…

MALICIOUS

PDF

83.2 KB Created: 2021-09-09 06:05:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 641edb1eae8e1b27bd7b6d8bf0fcc767 SHA-1: 91cf4bbcb456500503c591e67830f23570553fb5 SHA-256: 555c109676e687e3b576c9722b9beb04fddc2c84b8987089a09e2b194f1822be
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites 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 distributing further malware. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically highlights the nature of these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/c472c5a0857195bc0a1769e249e3314e/93296208596.pdf In PDF document text
    • http://bongoes62.dk/userfiles/file/kodobexujakoketemu.pdfIn PDF document text
    • https://senesi-sklad.cz/userfiles/file/54007193466.pdfIn PDF document text
    • https://advik.net/userfiles/file/zojuxofumogovim.pdfIn PDF document text
    • http://sjhtractor.com/d/files/jokudiwup.pdfIn PDF document text
    • http://metrocars.london/survey/userfiles/files/laxojusugexirixege.pdfIn PDF document text
    • http://controldellaves.com/app/webroot/arxius/file/sopewajaxasomowafovopopa.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/16394090192.pdfIn PDF document text
    • https://macroedunet.com/userfiles/file/xagiwulomedizevawesutuso.pdfIn PDF document text
    • http://archissimo.eu/userfiles/files/20702172772.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161333aec512db---mawigevawe.pdfIn PDF document text
    • http://diamantina-joaillerie.com/ckfinder/userfiles/files/93643528646.pdfIn PDF document text
    • http://problemconsulting.com/img/download/files/tewelimovi.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16135e5c74bd4c---97490917000.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161351c3d0a023---72439325727.pdfIn PDF document text
    • http://imailbox.nl/images/uploadedimages/file/9279373220.pdfIn PDF document text
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/xesavot.pdfIn PDF document text
    • http://lignumweb.com/site/webroot/uploads/files/jolifupimuzusepesineza.pdfIn PDF document text
    • http://baugeraeteverleih.de/benutzerdateien/45746624265.pdfIn PDF document text
    • https://purevdavaa.mn/uploads/ckfinder/files/91924008272.pdfIn PDF document text
    • http://skrutit-probeg.ru/upload_picture/file/wunelojog.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/161341490a0b11---gabetubejudapuxuzopulu.pdfIn PDF document text
    • https://weekendtripskolkata.com/userfiles/file/wosufiwodemalonax.pdfIn PDF document text
    • https://peoplesmodelinternational.com/ckfinder/userfiles/files/65427539869.pdfIn PDF document text
    • https://noventa.cz/media/files/file/34365734659.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=boot+animation+android+vs+applePDF 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_off0000e19e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE19E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B5 10672 bytes
SHA-256: d3fffc1854d448702fa8e730d9db110f5c1ea5c47cd1946f10dc93acf971c30b
font_02_sfnt_off0001122a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1122A 17436 bytes
SHA-256: 0003f8bc2e4a57c2aa9442660a9fe20a9daa4873e339e7a11fbb9f02b8cea707