Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5583d935dcd4de5…

MALICIOUS

PDF

85.7 KB Created: 2021-07-02 18:42:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: cac6e88d0bbf3300af15dfa5aaf4054f SHA-1: 78bc9dfd9e3f46efabbc497dc4637a804d443a43 SHA-256: c5583d935dcd4de556e4a56d236d969c1f6869f4b882d5d983601fba881e7b34
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the PDF structure itself is the attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac3030041b2---fonamuwab.pdf In PDF document text
    • http://roocenter.ru/upload/file/33233414054.pdfIn PDF document text
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c294b5dd08---45217291417.pdfIn PDF document text
    • https://ottenburger.com/userfiles/file/36535730639.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/2f10fbf8fdea2d0a7345fc8a0cd78c1e/pajavelunolodo.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609d9fa42f46d---fosuniwokegogiso.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/59556800143.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607fde1a60f75---45129820972.pdfIn PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/tixesapiwub.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/7m6ac53vdshga73goko9u4rdc9/84742875235.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4d201c56f---4404426556.pdfIn PDF document text
    • http://xn--80aagkbrca3apkgkee0a1bi.xn--p1ai/ckfinder/userfiles/files/bopimazumebafewejokuj.pdfIn PDF document text
    • https://educhina.mn/editor/files/wibik.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/8a301679187e90846001212ad6c8cb58/vovakelopoperavob.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608992054eed5---7883857700.pdfIn PDF document text
    • https://isosklo.cz/uploads/80101342195.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/aaa65a90233fbcaf0d49e30dbb8a4d70/xawiwatatu.pdfIn PDF document text
    • http://circolosilverblufitnessclub.eu/userfiles/files/tajotagapewepom.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085ff20800b8---vamedelokujogosaripez.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086a440191b7---figumanegisuzalogiwasufel.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160782b8707547---nuwogedokuxezamimomitib.pdfIn PDF document text
    • http://inlovehuahin.com/file_media/file_image/file/redejizija.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/ece760fe6650fc8ffd5d26a6653aaa41/76876594047.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2e56d37b4c---8625926630.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=how+do+you+strum+a+ukulele+with+your+fingersPDF 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010259.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10259 16668 bytes
SHA-256: debbd650353dcaa826028bb51a4d32ccd8d03775a5c79fc27be202335284081c
font_02_sfnt_off00012da2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DA2 11184 bytes
SHA-256: 53f9b36e4975e94aa4674a2c033cc461c85e7f3417d33bb7fcc9084d73e710b3