Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1639284fd47dc2a…

MALICIOUS

PDF

88.3 KB Created: 2021-07-13 13:42:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: cc4e66fce3fc4987c5d41bc8bc2c701b SHA-1: ea97fcb7a8f670c9ced1f24d9f4af5fa51835377 SHA-256: a1639284fd47dc2af3b06662bc837832bcc818969c31d895dab33935dd938a9e
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The file's structure and URL patterns are consistent with a link farm designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://krisoc.ru/uplcv?utm_term=library+manager+cover+letter PDF link annotation
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d0bf3dfd6---jakemarikamejeposesanaf.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5c21c161c0---52074162583.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4aaa0a56dd---47937241417.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/71052028936.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/7jfbm6st5e6cf0fuve79bq38aj/zoxenamisobexisozip.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/bejexuvewizimabure.pdfIn PDF document text
    • https://natatourism.com/userfiles/files/45899898966.pdfIn PDF document text
    • http://edu-family72.ru/content/images/uploads/file/sadebekiz.pdfIn PDF document text
    • http://frangarcia.eu/upload/file/vesudu.pdfIn PDF document text
    • http://bulongvungtau.com/media/ftp/file/64535721655.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608711944bbdd---wigaxumuvos.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4373890217---kudinina.pdfIn PDF document text
    • http://richmediahouse.com/admin/uploads/file/15313252887.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/44206819243.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607a0c49743f3---zabupekeguv.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160727fc1d905e---2494899764.pdfIn PDF document text
    • http://aptatravel.com/clients/4/48/489dad2d2d8436d4c085fc0ccdc2d1b3/File/14980997916.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/bf3f90bb3b1587d3cab37496b4c93a57/25264435695.pdfIn PDF document text
    • http://creativetechno.in/userfiles/file/xajanokagemagevadomoki.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/68185673210.pdfIn PDF document text
    • https://angelsstaff.com/uploads/file/pupalaseradinivewusulimu.pdfIn PDF document text
    • http://proxima-design.cz/files/file/64075602642.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b54c51ca9b1---30265658054.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ed100936c52---vegagozeti.pdfIn PDF document text
    • https://nestaerospace.com/uploads/file/jariranotowujid.pdfIn PDF document text
    • 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_off0000f53a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53A 10680 bytes
SHA-256: c1c864c58bd7cf9855b61c27085138acf36451c1f7dae4d73523146d562192f4
font_01_sfnt_off00010dba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DBA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000125cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125CC 17436 bytes
SHA-256: 44970cca2d3caec81dd7fac81e828e50d09b2ffe8f75717afa2da292eab37d97