Malicious PDF — malware analysis report

Static analysis result for SHA-256 e87fa50e94c239ef…

MALICIOUS

PDF

72.2 KB Created: 2021-06-11 04:25:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 4275eff226b191783ff6f280f14806f8 SHA-1: 70bf0f2a6bc4bcc06d243c7c15561b8261075d32 SHA-256: e87fa50e94c239ef9fdb60ed97df6746a27d4cdd5c7a03e61d8d2e8748949283
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to compromised websites, suggesting the document acts as a link farm to distribute phishing content or further malware. The document body, though heavily obfuscated, contains references to 'Word to pdf exe' and the authoring application 'wkhtmltopdf', indicating a lure to disguise its malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://synerhu.ru/uplcv?utm_term=word+to+pdf+exe PDF link annotation
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/9g0rfv79fm1lc1257c8rd3cca8/kunurot.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608b609c85582---9763591610.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ff1ab0d29e9b43bb51ffe87e124b4b04/xunefezewizog.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/0d7cb892d858e31303511ecc174c8d91/30057668540.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a29a0348c43---kumozulelojuwoluxi.pdfIn PDF document text
    • http://firanywiktoria.pl/uploads/editor/file/xotow.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/adaf3e9d18b64241497d310a6184d296/4291867993.pdfIn PDF document text
    • https://kisikana.hr/userfiles/file/11804584721.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1606cc46d5d0b8---14856373930.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160725bb8aadca---72233105312.pdfIn PDF document text
    • http://mbcasc.net/imgs/file/fefopozebubixuxuxoz.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160905e1143352---75713624176.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/e717e66bc285476a0fdf9b2ea31b02b4/gofewivodebajazuno.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/mjbe4e3m9fsrkqb9u3r0ru9fn1/99924319441.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7a8f2ecbf---lunivivudojadakudamos.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_off0000df3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF3B 4696 bytes
SHA-256: b10e38e82beb5bcf284a2774ea0f76d6ff8e46f66d33dfdaf717d2238bb0cd71
font_01_sfnt_off0000ef5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF5A 11288 bytes
SHA-256: 171a034b5d07a9c1c5d95e230748403011ab4d59eeb08a08e247b2373ccefb46