Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5a5db40728a1ec6…

MALICIOUS

PDF

84.0 KB Created: 2021-09-15 22:19:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1aacc56f5f167c999b64c90d483fb5d8 SHA-1: 58b7fafec55347c1023d20af6f6cc944558083e9 SHA-256: d5a5db40728a1ec6e97b81afb09dafeff5f1384fa471fc925750f20ca8ce0c1a
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of multiple external URIs and link farm heuristics indicates a strong intent to direct users to external, potentially harmful, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://krisoc.ru/uplcv?utm_term=best+free+android+plant+identification+app PDF link annotation
    • https://visualarchive.bg/files/nuzesuredene.pdfIn PDF document text
    • https://hizlipin.com/calisma2/files/uploads/golopulezej.pdfIn PDF document text
    • http://runnersavezzano.it/public/userfiles/file/luzakujewibizu.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16140a3fa169cc---27394928182.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411c3357560---gexaniwatekizisabid.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/kopaxifu.pdfIn PDF document text
    • http://newworldss.com/uploads/file/54213368049.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16140cc6c098a4---robav.pdfIn PDF document text
    • https://christianbelieversmatrimony.com/web/christiansbelieversmatrimony/photos/ckeditor/files/6219058151.pdfIn PDF document text
    • http://degrossier.nl/uploads/file/83411829099.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///95949873198.pdfIn PDF document text
    • http://dezis.ru/uploads/files/84498000036.pdfIn PDF document text
    • https://niboparis.com/upload/fckeditor/files/kolujivegoxobena.pdfIn PDF document text
    • http://art-wonders.com/ckeditor/ckfinder/core/connector/php/uploads/files/41151087778.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9bde1a61b---38309272787.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161410429c424e---muniremefi.pdfIn PDF document text
    • https://familienbilstrup.dk/userfiles/file/nelemumilorufusibu.pdfIn PDF document text
    • http://nigerseedindia.com/uploads/93165173641.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613ec89fc4107---navegajoxas.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/827f30d5038876ffcdcdf7afa8cdb08d/77194341999.pdfIn PDF document text
    • http://sterenstein.ru/userfiles/file/katodamizimozid.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/b8b6036641395d8183f946141f86356c/tumanesezemazajerugu.pdfIn PDF document text
    • http://ideviceplus.be/app/webroot/files/userfiles/files/57834593261.pdfIn PDF document text
    • https://norservis.cz/files/files/19388489321.pdfIn PDF document text
    • http://conhantaoankhanh.com/webroot/img/files/guvituv.pdfIn PDF document text
    • https://drnanemilk.com/tctt/sites/aaa/file/rodazinofifeni.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_off0000e308.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE308 17964 bytes
SHA-256: 5cb1706974d72290db2d6fa15b102787fbd456a51d8f126c96c3e00700f024a2
font_01_sfnt_off00011185.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11185 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001299c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1299C 10668 bytes
SHA-256: 9c243f634add9afd2377225296bdb1dec46c79cbc0838ce7b23a5f2f9d611195