Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4b99b1551403a5b…

MALICIOUS

PDF

75.3 KB Created: 2021-07-18 01:44:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: f169f392ae6e4b02e48d1e0bc092f6ed SHA-1: 8e6a19b9d926be8bb4f58e445b3f2c8382b0a670 SHA-256: f4b99b1551403a5b33cfedb913b4adc2416c8174765458329181e681c8dad971
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress upload directories and other disposable hosting sites, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://septumdent.com/img/userfiles/files/8038174751.pdf In PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/16076add914d4a---vuketumowuga.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/4748469c22ce480589698fa0ce9fcacc/67112874282.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/c6bbb16c988fe1a0df93f6997b047fb5/91689171340.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160de1e6dccf4c---83198940972.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf643a51d5b---mufowixoselivifex.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160840e63676a8---kewum.pdfIn PDF document text
    • https://magnettoptan.com/upload/ckfinder/files/47287975757.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/502b5bc43c4e22458d5f417480decd48/vafasivejawikoga.pdfIn PDF document text
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16071bc5af33a0---94487457378.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/8ea5bb2f7a8b3773dd00f5f1ce06a4f3/95833249193.pdfIn PDF document text
    • https://www.proctoloji.com/wp-content/plugins/formcraft/file-upload/server/content/files/160710fb586aa5---sigolovufozamuzad.pdfIn PDF document text
    • http://www.tekkoo.net/images/library/File/bowabevelofux.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d7297bba3a---14951056656.pdfIn PDF document text
    • http://www.trackls.com/application/ckeditor/ckfinder/userfiles/files/97923500157.pdfIn PDF document text
    • https://bayihoki99.com/contents//files/44026535760.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/160eca963bc889---wupegizidezo.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/92148750161.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160767a7c179f9---viragewubasaxalusowodepi.pdfIn PDF document text
    • https://www.apartamentselsllacs.com/wp-content/plugins/super-forms/uploads/php/files/ovtp0ui6uq5tvo0tsp172da8j2/gibijojuzidila.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b1326566e19---fuwisolatidakukefipax.pdfIn PDF document text
    • http://ownlines.com/upfiles/file/40342809143.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/us44jrftqp6kn7oc0fjkfp0tb1/46540683193.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/6188bbbfaac104337baabb6007ab5a7f/1137136413.pdfIn PDF document text
    • https://vate-tire.ru/wp-content/plugins/super-forms/uploads/php/files/30f041ea6971a57ff2ec508f665aea61/32466542979.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=amc+theaters+orland+parkPDF 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_off0000c356.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC356 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB6D 10760 bytes
SHA-256: 6f2fee1da8e799b9e0b2eb79b16955e8bea2d4a3c135861cebfe181003208e8e
font_02_sfnt_off0000f405.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF405 16732 bytes
SHA-256: 5910d937a56b8c30f118729b6188e80d7eddd75ce16e72252bb9efc519a77382