Malicious PDF — malware analysis report

Static analysis result for SHA-256 a820e3acd73b6f8e…

MALICIOUS

PDF

77.0 KB Created: 2021-06-12 01:23:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 98b90d74496872e20207a596c0e62f71 SHA-1: 8549e10e6e1f5dd55977c6029d81e39cab45e409 SHA-256: a820e3acd73b6f8ea051a7d7b5396c27923991a2c9d7a4f41e8e864761b6a2a9
156 Risk Score

Malware Insights

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

The PDF file contains numerous links pointing to websites hosted on compromised WordPress installations, indicating a link farm designed to lure users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, but the primary malicious functionality appears to be the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://catamma.ru/uplcv?utm_term=best+video+templates+for+kinemaster PDF link annotation
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16077cef40ecb5---71507153389.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/160b105b55396e---wigataxepofezakurowugug.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/64937612302.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607db8eba88bc---weginativigupu.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/3r6uom985q1ep9vndrk1klc4t7/wewir.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/unr5s3susqbul6930sm2rfj101/tixoratenebapurorupez.pdfIn PDF document text
    • http://megaprestige.ru/uploads/files/waxotutegifijawaw.pdfIn PDF document text
    • https://go2germany.ru/files/file/91910312785.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a0304a66e42---kubosalisulefekefumezir.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/20242095637.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/54601595710.pdfIn PDF document text
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160999ff4ef684---mifajakipebivutupek.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/6co0550oqhfqsjjlqmc2kl5a5q/lovepalolemanatobad.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/8sme86h4kn27j704nb3s80ot99/borugijowi.pdfIn PDF document text
    • https://globalazeri.az/wp-content/plugins/super-forms/uploads/php/files/pbu972qj3k0hpg1srn3svhuco7/48749452902.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f02d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF02D 5360 bytes
SHA-256: 27b29c467a0db2355dda371ee796a435fd47679cbbe2a80236aeb3639731fee0
font_01_sfnt_off0001025a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1025A 10848 bytes
SHA-256: 3cda7648f5819b1bf12f5f9229f027fa0d27360bf748133bb8f2f20ca5290603