Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f763bfc34a90377…

MALICIOUS

PDF

74.4 KB Created: 2021-09-19 17:30:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d23e27a3fac2b923a7f44bd4e1a1fffd SHA-1: a898c87c1302550d44fda8f76a8b338c9794cc9e SHA-256: 4f763bfc34a90377af53824497f0e1903503f62916fbdaa480966cd5f423d097
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The PDF's structure and the nature of the URLs suggest it is part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://driver-jazda.pl/upload/file/98771826520.pdf
    • http://medica-eg.com/userfiles/file/sozajejobisaworinepa.pdf
    • http://namkhoabacninh.com/images/files/wipabowemugadawodonol.pdf
    • https://valubil.com/public/uploads/cms_file/cms_files/sirireroget.pdf
    • http://jonme.net/ckupload/files/vujabokamikusuwowotaru.pdf
    • http://puginternational.com/ckfinder/userfiles/files/73049509465.pdf
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16135c00e1563d---nisoxezadefanumas.pdf
    • http://montesantangelo.it/files/files/73262834207.pdf
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/f89ae5rkcc7pn8lgfim1hcmlkd/26864828077.pdf
    • http://a-pluset.com/userfiles/nitowovupaxelawisupapud.pdf
    • http://zoekidsworld.com/userfiles/file/tovuxavevowudizodowe.pdf
    • http://kingalbertltd.com/uploadedfiles/file/vikizoz.pdf
    • http://agedwedfjtj.pretty-match.com/upload/files/niguruxi.pdf
    • http://fibertechnique.com/tmp/file/xapiriwa.pdf
    • http://rtm-plus.ru/ckfinder/userfiles/files/41944186209.pdf
    • https://granitabrasive.ro/editor_up/fitabenabarapavumasujamuk.pdf
    • http://etenindex.nl/images/uploads/paxigoxiduxezesor.pdf
    • http://ags-sib.ru/ckfinder/userfiles/files/76167561773.pdf
    • https://uzunlarpeynir.com/dursun/upload/files/94682542638.pdf
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/416df27d274165e7522592fb430ce738/64274084468.pdf
    • http://www.hydro-tg.pro/upload/file/22526659654.pdf
    • http://nacyc.jp/Upload/file/nafen.pdf
    • http://itnetworkconsultingsf.com/helpdesk/app/webroot/img/userfiles/files/96655828357.pdf
    • https://onhimalayas.com/ckfinder/userfiles/files/fekorumonup.pdf
    • http://kondicionery-ivanteevka.ru/upload_picture/file/78052027511.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=smash+bros+3ds+iso
    • 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_off0000c186.bin
38db530ac6b0bde7290f73ed15f97c35ed3d6f2e8e9f6ead952fc76e55b028a8
pdf-font-stream PDF embedded font (sfnt) at offset 0xC186 16724 bytes
font_01_sfnt_off0000ec5b.bin
fd338c57b239b54d6759fb9ecf0c81a3a3ca49b83e39f8263187865df206ab1f
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5B 10520 bytes
font_02_sfnt_off00010438.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10438 16792 bytes