Malicious PDF — malware analysis report

Static analysis result for SHA-256 55503c39d651ec1b…

MALICIOUS

PDF

78.3 KB Created: 2021-09-05 08:18:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 67f7a6d29ed609f3c6020b9a218bc1df SHA-1: efd44f62d016be43f416acd0c4cbd6d590cd3d8f SHA-256: 55503c39d651ec1b3883da54ded27ebc64b3237f9a57ffee9fc877e8858a7d76
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm hosted on compromised WordPress sites, with URLs pointing to malicious PDF files. The 'free download pdf reader for win 10' UTM term suggests a social engineering lure to trick users into downloading malware. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075083e15b2a---30949590285.pdf In PDF document text
    • http://worldtile.net/jangheung/userfiles/file/91383284487.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfccf9136c---xemotodarutefunofowesisem.pdfIn PDF document text
    • http://romengo.com/ckfinder/userfiles/files/8320601797.pdfIn PDF document text
    • https://napraforgohotel.hu/upload/file/69806547655.pdfIn PDF document text
    • http://moje-stranky.eu/userfiles/file/90410290007.pdfIn PDF document text
    • http://ugyvednok.hu/userfiles/file/19785908668.pdfIn PDF document text
    • http://win-sonic.com/ck_imgs/files/lixex.pdfIn PDF document text
    • http://cwesp.biz/upload/file/lefap.pdfIn PDF document text
    • http://pumarecovery.com/userfiles/files/loxojufaxijeku.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/98e5946a56ab9e20bd32e5eecc287f0c/55823835432.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a78c1be616b---vaweraze.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075dd1d6767e---nolekozadidezeronexusevax.pdfIn PDF document text
    • http://leasingtowers.com/ckfinder/userfiles/files/94530162557.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/15654908482.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce1c940070---52567168634.pdfIn PDF document text
    • https://sgpropertylawyers.com/wp-content/plugins/super-forms/uploads/php/files/6bba052af9fd80c696ca31b912a50304/78929319345.pdfIn PDF document text
    • http://mya1fc.com/files/ckuploads/files/56154749502.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/84734029233.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/16108cb63512d6---norafemavawakafom.pdfIn PDF document text
    • https://eurosan.pl/user_images/file/27215143887.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=free+download+pdf+reader+for+win+10PDF 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_off0000c4c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4C3 20792 bytes
SHA-256: 909772e90896022fefd3d0672e0cda887834663dc6deb808734022f7e4a7deb1
font_01_sfnt_off0000fbb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBB6 10464 bytes
SHA-256: d0d95871e194c46f5f6fb4a4be5cc9e950c8dc340518abb9943eb8a4fa7526a4
font_02_sfnt_off00011391.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11391 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1