Malicious PDF — malware analysis report

Static analysis result for SHA-256 f23e16110d8b1237…

MALICIOUS

PDF

82.6 KB Created: 2021-09-07 22:51:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 61f5d90a1fd319f96640fc69c0977924 SHA-1: ecd031a67c83143a1bb16adb0eae59eca2161f25 SHA-256: f23e16110d8b1237a4638ba558c07b9242c78414661edbea7511dec2f51c6642
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV specifically identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs, many pointing to disposable hosting or compromised CMS uploads, suggest a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the nature of the PDF and the URL patterns strongly indicate it's part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://www.ddu-hk.cz/ckfinder/userfiles/files/kizugewis.pdf In PDF document text
    • http://clairvoyantinfotech.com/demo/images/dutomipugatugipamafakom.pdfIn PDF document text
    • https://www.twibiotech.com/plugin/ce1/ckfinder/userfiles/files/wadevijileguxexigodoto.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/tpf40aflr8k2t1qmp702nuerr2/sebupipamivudoxon.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/7e7385a6b11a478f17a00d8eb7c990b7/1254362138.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/kadepa.pdfIn PDF document text
    • http://soeurs-scjboran.fr/soeurs/upload/files/birukivezadalib.pdfIn PDF document text
    • http://eortak.com/img/fck_temp/file/93911221009.pdfIn PDF document text
    • https://kermanrooz.com/img/files/99354157174.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/ramijopoxirupelejaf.pdfIn PDF document text
    • http://www.hgbehringer.de/img/files/files/zalibasomasisuf.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/os96su63bc3pm4amuv0ue0mclm/91972646948.pdfIn PDF document text
    • https://signika.pl/Upload/file/14410519972.pdfIn PDF document text
    • http://lindendirect.com/ckfinder/userfiles/files/73411506661.pdfIn PDF document text
    • http://www.giuseppe.ru/ckfinder/userfiles/files/87760938495.pdfIn PDF document text
    • https://haidangpc.com/contents/files/40565664458.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16076a4954771f---68450756320.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/7a8782deb42aad11c25528dda3255283/somanisolo.pdfIn PDF document text
    • http://cctechlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/85795155078.pdfIn PDF document text
    • https://mclandpin.com/calisma2/files/uploads/50387407786.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/7d4de7f57f05d91121b810fa3d75ec98/superotorimijabisesoxidog.pdfIn PDF document text
    • http://simonhoirup.dk/userfiles/file/xevopugukosejazaxozit.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=neotropical+rainforest+mammals+a+field+guide+pdfPDF 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_off0000dbe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBE0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F2 17848 bytes
SHA-256: 6f7b112ac2983986b2caea386a49014e5db9dbd3c88d0279806c7d3ccbbed20f
font_02_sfnt_off0001228f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1228F 11040 bytes
SHA-256: d4396756e0044ccee536e85ba16901ee2026e63c2ad13ec6ebad456771b29879