Malicious PDF — malware analysis report

Static analysis result for SHA-256 24a853609fd1636e…

MALICIOUS

PDF

91.1 KB Created: 2021-08-28 20:23:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a7fb3867da114136315e8828de159b6f SHA-1: 36064ad0d28923494e80e282741107b33c88d80c SHA-256: 24a853609fd1636ea78fbebba783c310a075f33a9cab073342071847f38b826b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as containing a link farm pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV also identified it as malicious. The document body is heavily obfuscated and unreadable, but the presence of numerous external links suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9906

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://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/6c861946cf10b80f2a552c7926430e87/50020416189.pdf In PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/15e9ebf4621385302a9cd3a54afbff39/juzudevavefifunavawamila.pdfIn PDF document text
    • http://ytlcases.com/userfiles/file/68224193770.pdfIn PDF document text
    • https://medtek.vn/storage/file/tozowir.pdfIn PDF document text
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070366d3cb42---pitikarigub.pdfIn PDF document text
    • https://tolgyesvolgy.hu/userfiles/file/47660755238.pdfIn PDF document text
    • http://itkaufmann.com/images/fckimages/file/mimupegateberojasir.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ab764dd0f1c---fuxug.pdfIn PDF document text
    • http://mirandatutoringcentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b4f2771dc18---xenumirobidikatezam.pdfIn PDF document text
    • http://gekon.net/userfiles/file/13323148606.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607eb3f53504e---96013645197.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/160741eb33d050---73338528169.pdfIn PDF document text
    • http://palazzodiaz.com/userfiles/files/14496235362.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/14167287ae3c5735792128aed233fe00/66511181059.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/6mjq6f8g6ranjse3ehjvgoldkc/88284480321.pdfIn PDF document text
    • http://bavlas.lt/ckfinder/userfiles/files/samulibobafobagutug.pdfIn PDF document text
    • https://gbagencement.fr/uploads/file/deradorokaweliwedefeju.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/a551c2c964ae5c657b8b0a7ff46472c8/doxifikevazepijopusimipe.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/kesilofimivizefuwekijumuz.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/22512029232.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160b67285da3ce---rijugupunupusimanitavajax.pdfIn PDF document text
    • https://floridaholidayplanner.com/wp-content/plugins/super-forms/uploads/php/files/55db7991a72e5411a56fb86162f9da70/bagelaletu.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/lemamulefafam.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c7b3076ff8f---10541978361.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/915pbomcjk5sugvtbfvookm5j4/venarofesuvoruwogexela.pdfIn PDF document text
    • http://yizhu580.com/ckfinder/userfiles/files/vujujapuxoginugejezojiw.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a64c9eee8d6---54117865051.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=one+on+one+meetingPDF 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_off00010150.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10150 18308 bytes
SHA-256: ce9890269fcd1764f9f88a744ced6863f1afb6603934e856217f7894e1c2ba4b
font_01_sfnt_off00013081.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13081 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014898.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14898 10000 bytes
SHA-256: a23bba58bd0501e6844ed51de5d9ed8e82e8b07384092f387c6b74968b933a9e