Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c5b07faf1a679d6…

MALICIOUS

PDF

76.2 KB Created: 2021-06-24 21:15:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 886f350e450e4fb81e570df8ceb41af3 SHA-1: e1a9f6d1ace7bd2a67c701d5d98bbd693126af34 SHA-256: 1c5b07faf1a679d612435758e8139d2f66f85b8b4366dabf6902c3b50fda4835
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier, indicating malicious intent. Heuristics identified it as a link farm pointing to multiple compromised WordPress upload directories, suggesting it's designed to distribute further malicious content or phish users. The document body, though heavily garbled, contains references to 'wkhtmltopdf' and 'Qt', indicating it was likely generated by a tool rather than being a legitimate document.

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://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607fdf5b74ee0---vopubenapelifugawozuzim.pdf In PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c45d7a53772---93943538060.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/m5b0lvh9u1dkilbi71efp3g35s/fasikerokula.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/n5fhi4fni1jb1c0bor90u9pnp3/vilozuzozanubimuneba.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/bfcdf831bf7aba6227e211ba429b602a/23179805210.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160812a84a997e---19501346131.pdfIn PDF document text
    • https://www.ideaklinikankara.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cfd635fc82---votibizog.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/9fd8e4a4057ad0bdf0798a6e36457236/sawepas.pdfIn PDF document text
    • https://canionglobal.com/FCKeditor/file/sosejodugekegewobe.pdfIn PDF document text
    • http://badischer-kunstverein.de/ckfinder/userfiles/files/59244473189.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b6622e7c21---runugovuxaro.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/d4rldt9tor87kpuic8lmdut68d/69087141060.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/xisenem.pdfIn PDF document text
    • http://orgue-chantepie.info/FCKeditor/upload/file/nazososabelawumes.pdfIn PDF document text
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/if1fkdl155je3cns6qpi6strj0/1313238707.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=below+her+mouth+english+subtitles+onlinePDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC29 5172 bytes
SHA-256: 1613083108a4de169cd88709cccecd9dc05e1fbe68254cddf9013274e2410b4c
font_01_sfnt_off0000fdac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDAC 10676 bytes
SHA-256: efc284314ad1e0d043a11005bb566c6b4180189837f1e1e1ca159f8be642fea4