Malicious PDF — malware analysis report

Static analysis result for SHA-256 e423e871ff26a67c…

MALICIOUS

PDF

69.9 KB Created: 2021-06-08 23:45:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 5a537e07307b82871430c6e614ab6b1b SHA-1: 91ffcce9ece9e6934e73610c3bfd9deff1aef6b8 SHA-256: e423e871ff26a67cfe9c37792465dab3c5c8f69a120c05e457adb222851db8d3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a phishing or malware distribution campaign. The document body, though heavily obfuscated, contains text related to a medical textbook, likely used as a lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to PDF-based phishing or exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://archism.ru/uplcv?utm_term=washington+manual+of+medical+therapeutics+36th+edition+pdf PDF link annotation
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/a0fb900587d6fa61197707c5030cbf66/zekimedodulugukutagegux.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/1541db81a14fc139cc7b300de796fc06/pukakelajananamexekegusu.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/ure1qcj4ff2r66qgse0korg9l4/kekederitetegikeziren.pdfIn PDF document text
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/f20453271181d3a60b7b35f9c507887a/gaselafowixilev.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16087c29643cea---1010274130.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/u9bfdtu8fhtrcqplih3bcov2u0/jagafolamures.pdfIn PDF document text
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607450c02623f---19131497659.pdfIn PDF document text
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607d6d45a1a77---83043096361.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/8ea227e4735b389f8eb03f507c354165/bifuruzutesigasazawamuki.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/c5d51876496ea64baa822ab0c26becdf/14083685896.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160810222a2d39---33023981605.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b24188c581a---75021207197.pdfIn PDF document text
    • http://gulfcoolcontracting.com/uploads/userfiles/file/file/nijupowemem.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/77877103465.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cd985164ae---budifanesosigaxalej.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/dabbaa2a9fb4c6b267f0db1fb1760777/34667344883.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_off0000d2fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2FE 5900 bytes
SHA-256: ce145f42de66a31a6847ffd9517c0c1efc9c9b1641770fd3c1c0c38384de48d9
font_01_sfnt_off0000e6fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6FA 10292 bytes
SHA-256: 078a20c5b46f4a28518d6414e097151ed0ad760a50eb43c56a3e0a9b000a6cbf