Malicious PDF — malware analysis report

Static analysis result for SHA-256 55d1afb10ff1f122…

MALICIOUS

PDF

82.4 KB Created: 2021-08-29 15:21:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 98b59831998d3fb1436d2317d5035217 SHA-1: fab311d1e036d952e89304d9fec4978f78c83239 SHA-256: 55d1afb10ff1f1229840087eea1a516a2c17a8d742b28bfb4a04a63b94b93110
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV and an ML classifier as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS upload directories. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and URL analysis strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611f04c765be8---fumuv.pdf In PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081b90c30f02---legamibebedeja.pdfIn PDF document text
    • http://3e-machinery.ru/app/webroot/filesfiles/72906352794.pdfIn PDF document text
    • https://turismopontevedra.com/ckfinder/userfiles/files/tezupuvomug.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d537917edb---91452959574.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/595ec4ca79b8742518cc3f321a086874/kifuxanaxileze.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/3a3dcef5998e39bb72423be5c5971f7c/34262143550.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/rocghni7dth7cbl4de8a92t2un/30529617497.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf350b9808---61194693396.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/16089f7ccae87e---lafudawivopenexani.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210813_348170D4C49FBA22.pdfIn PDF document text
    • http://produccionesproezas.com/clients/2/28/28ea8f13eb032e89cab2838ec144e7af/File/dazix.pdfIn PDF document text
    • https://terlickodds.cz/www/www/fckphotos/file/64924275105.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607ec77316f84---13108466351.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/h0gvct56hnsapjkgsni9lv0k27/23481882258.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/r9eqh45ts38fchomqk6p24gih7/84321017891.pdfIn PDF document text
    • http://winhazel.com/indigo/ckfinder/userfiles/files/54522922407.pdfIn PDF document text
    • http://anhopphat.com/uploads/files/44700530719.pdfIn PDF document text
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160c14de9214e2---78917658563.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160cbe2217a1bc---zujudiwuvovikupabad.pdfIn PDF document text
    • http://adbrf.com/files/fckeditor/file/88831247611615c1992a4.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/d50d4d5fcce292bae112c907c5fdb733/punasok.pdfIn PDF document text
    • http://ski-experience-japan.com/images/blog//file/jajizososerina.pdfIn PDF document text
    • http://itkaufmann.com/images/fckimages/file/fidivedewokujorawam.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=beef+and+broccoli+stir+fry+healthyPDF 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_off0000d970.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD970 10880 bytes
SHA-256: 6d527cfa5c4db0c054027dff39cfb13350f42f90ab61570f2808a602be92ac74
font_01_sfnt_off0000f28a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF28A 17800 bytes
SHA-256: 18a215e2b4e56fab0cbb54430c374e33ee2da41dcf229918876a823b906963b8
font_02_sfnt_off00012112.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12112 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1