Malicious PDF — malware analysis report

Static analysis result for SHA-256 18fe3f9b646c113b…

MALICIOUS

PDF

70.4 KB Created: 2021-09-24 19:26:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 4a92235ea78562508a6eb6fdfa942512 SHA-1: 68970c37eead2b37f12308d7798d8ce16810c52f SHA-256: 18fe3f9b646c113b059519c6d4dee6aa8d8064dc1235baa585e0f8c49714ce26
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, but the URL structure and heuristic firings are sufficient to assess the attack pattern.

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://nomylo.ru/uplcv?utm_term=feenstra+advanced+international+trade+solutions+manual+pdf PDF link annotation
    • http://yejida.com/userfiles/file/68306662732.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/1b56mm1l85vfnhluesleh2g7ca/79752977470.pdfIn PDF document text
    • http://ledseoul.com/userData/board/file/7832538288.pdfIn PDF document text
    • http://reklama-kemerovo.ru/files/files/kudajudejegodivolizuxid.pdfIn PDF document text
    • http://xpeedon.net/userfiles/file/20210914203136.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16139532a4fe38---93696711681.pdfIn PDF document text
    • https://m-isc.com/userfiles/file/vakizamiwujilulaluvimewum.pdfIn PDF document text
    • http://reelproductionshd.com/userfiles/file/71519845881.pdfIn PDF document text
    • http://aaykpn.com/uploads/editor/files/jesadow.pdfIn PDF document text
    • https://glamweddingdesign.com/userfiles/file/texelar.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/161316391cd524---75488029104.pdfIn PDF document text
    • https://taiwancy.com/app/webroot/userfiles/files/dutinitaladegakusutudavi.pdfIn PDF document text
    • http://be-now.pl/userfiles/file/37449407978.pdfIn PDF document text
    • http://begemot-rus.com/uploadfiles/file/2021092111485673499.pdfIn PDF document text
    • https://foursservices.com/nbloom/fckuploads/file/zeteropepoju.pdfIn PDF document text
    • http://epmachine.ru/d/files/32791960530.pdfIn PDF document text
    • http://twilaw.com/files/files/kupusa.pdfIn PDF document text
    • http://sabaispa.net/userfiles/file/21361045273.pdfIn PDF document text
    • https://bbu.vn/Images_upload/files/remofikefapefupigeba.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/74625985471.pdfIn PDF document text
    • http://romengo.com/ckfinder/userfiles/files/38541893441.pdfIn PDF document text
    • http://otestmanager.com/club/data/userfiles/file/20210923040707.pdfIn PDF document text
    • http://hitmet.slektenkaas.com/bilder/file/66915326141.pdfIn PDF document text
    • https://hostsolutions.ro/app/webroot/files/userfiles/files/negafobek.pdfIn PDF document text
    • 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_off0000af43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF43 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c755.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC755 16572 bytes
SHA-256: ea2aa6f855506b71d46bf89da003f11118f4ca791e8c39788a5c6a9e6004b9b6
font_02_sfnt_off0000f238.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF238 10924 bytes
SHA-256: 02cfe4ec136ecda2b74321a0e18f4579bb08d43b5db28a82433d0e2be3b154e3