Malicious PDF — malware analysis report

Static analysis result for SHA-256 259a06f18d0c88b4…

MALICIOUS

PDF

86.7 KB Created: 2021-08-07 11:03:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 59479a14caccea89cef440f7033a05c0 SHA-1: d3f076abd07df907c58793645d6fc15ff2c148d1 SHA-256: 259a06f18d0c88b49920da813460dcf43494b4e96fdcbaab086029f100ffdfc4
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users to malicious sites. The presence of numerous links pointing to compromised WordPress uploads and disposable hosting, combined with a visual download button lure, strongly suggests a phishing or malware distribution attempt. ClamAV detection further confirms its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 8

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://aydinservis.com/ckfinder/userfiles/files/sapexumevesutesusukilajur.pdf
    • https://vietfun.com.vn/wp-content/plugins/super-forms/uploads/php/files/vfhvtn4ooon5vbu19gd1r2c3k4/jazurowemetekukiduni.pdf
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5a16bc8147---refiwirapapusuw.pdf
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/3ppkmmmqleonu1l7e1qp80t71s/tolokumopeseranisawidi.pdf
    • https://tranthachcaodanang.com/uploads/image/files/85971295521.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16099d0c54fe57---viwipituvu.pdf
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/b6d6046c8d4e774ed590336fb422a706/fonunisipomopusibolo.pdf
    • https://dovolena-jiznicechy.cz/uploads/13298894953.pdf
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1607b36f018b1a---82750666293.pdf
    • http://amandatour.ru/js/ckfinder/userfiles/files/44247460915.pdf
    • http://thaoduocvn.com/userfiles/image/file/vitidubulovozapunigej.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/khtjn2m3m49s8c7hnbqgm355av/57376667542.pdf
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16077496d8113c---fuletikak.pdf
    • https://lacecinella.com/writable/public/userfiles/file/41285639565.pdf
    • http://holidayservicemarsala.it/userfiles/files/biwebajepafurope.pdf
    • https://securitydm.com/slicice/file/28155609533.pdf
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b87a521c3fe---kafurevixiwur.pdf
    • https://watfordfairtrade.org/app/webroot/img/files/12728798091.pdf
    • https://verlauf-ekb.ru/admin/ckfinder/userfiles/files/63689447758.pdf
    • https://apinero.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607720958a850---nejibixepibifufabatiku.pdf
    • https://nada70.org/userfiles/file/4925206044.pdf
    • http://bitree.net/ckfinder/userfiles/files/botusuduxufofosu.pdf
    • http://iphysiology.ru/upload/kowabafikovavinujite.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+get+express+vpn+premium+for+free
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee00.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE00 16792 bytes
font_01_sfnt_off00010617.bin
cdc5e033ae434955134ab598dea768cbbd1da9719af97bcbb68c29f86733c551
pdf-font-stream PDF embedded font (sfnt) at offset 0x10617 10840 bytes
font_02_sfnt_off00011f29.bin
669c2f57cbd1b9078a278b63c7e44c738b8ba40e44df7aa06d37c596105b1dae
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F29 17416 bytes