Malicious PDF — malware analysis report

Static analysis result for SHA-256 3cdd86ce6f51b557…

MALICIOUS

PDF

83.3 KB Created: 2021-09-03 11:10:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2e20c3ebd3dfe171991f35b1fe598f49 SHA-1: 8439836864edef0ca50c12d72438d5568dfce358 SHA-256: 3cdd86ce6f51b557d3ded7c87d48c4818bc116d4ff8c6a8928a643b7753c6826
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. The presence of a link farm pointing to compromised WordPress upload storage further suggests an attempt to host and distribute malicious files. ClamAV detection as Pdf.Phishing.Trojan-d2568dad23a94d95 confirms its malicious nature.

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://funperm.ru/content/file/vuzonikezetotegukalobe.pdf In PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608934f8710e2---zowiv.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d9b8b57a5ea---74116183782.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/161294b0262bf5---37953777526.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607349fb36aab---binufumusifovizovawenevut.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/diwemuvutulorabis.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/52360839173.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ccd96fe6aa9---44286222171.pdfIn PDF document text
    • https://fereshtegan.net/basefile/fereshtegannet/files/zomijenibavudumisok.pdfIn PDF document text
    • http://carscaso.com/js/upload/files/lekesul.pdfIn PDF document text
    • https://willmarlakesarea2040.com/ckfinder/userfiles/files/vufoxulusugamemapike.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/75507924861.pdfIn PDF document text
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/40081f0dbdefe1a4000274a22942cdc7/nifopasuzidape.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/58140191778.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/218451df9db468dcc501342ba734d3bf/41255246103.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160882945c6c27---tadajaluwugepajunifajusif.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/wenijotiluvedasigovemuf.pdfIn PDF document text
    • http://bakkervoorwinde.nl/app/webroot/files/ckeditor_files/files/32614710898.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/f4n2c5gg7et6varsdsh67vu9k2/90559503605.pdfIn PDF document text
    • https://minipowerpack.net/upload/files/6470890205.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f4f19279176---gemejudiloxuxusajowaku.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=solving+quadratic+equations+worksheet+tesPDF 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_off0000de97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE97 11212 bytes
SHA-256: 675326ca022c6827204b9b89fbbddef9fa7303d8ffee747f6cc1ad4d73cdc363
font_01_sfnt_off0000f852.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF852 18148 bytes
SHA-256: a214bfc1fb6be33a08b329b758fd4dff392d0c085b520c3475d2f478e2d14ac1
font_02_sfnt_off00012781.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12781 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1