Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4825c6d7d552197…

MALICIOUS

PDF

101.1 KB Created: 2021-09-04 03:38:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8a8498f9886918245a27dddeb1eee3b3 SHA-1: e920633dc9068f67f613412fcced609a64411c82 SHA-256: b4825c6d7d5521973492b7e031158c14a28e9e9f67313b12a35af092afef1662
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains a large number of embedded links, many pointing to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f6d0323005---luvowarufajawi.pdf In PDF document text
    • http://khonggianmang.com/upload/files/wonuzefexegazawasa.pdfIn PDF document text
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/2f84662f0f081795d7cd8b00eb990d36/nudolupajuxuxu.pdfIn PDF document text
    • http://lawyerstitleescrow.com/clients/9/9b/9b7cfcecb5e5abb6b877b2b1d59b4eb1/File/98813619490.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca49482646---gupewazibil.pdfIn PDF document text
    • http://visit-pune.com/userfiles/file/39085356213.pdfIn PDF document text
    • https://realestateconnect.us/wp-content/plugins/super-forms/uploads/php/files/tv7k0d83alanmio0ls5ica0j46/54479990892.pdfIn PDF document text
    • http://kotolantopeni.cz/file/gewinuwaniwujakagoba.pdfIn PDF document text
    • https://tutorsbureau.net/userfiles/file/62841626938.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/86381bccd98ce86974972683a8acb973/bazawelakuvefeg.pdfIn PDF document text
    • http://www.peretprod.ro/content-images/file/42353722357.pdfIn PDF document text
    • http://l-max.ru/userfiles/file/30120151308.pdfIn PDF document text
    • https://upaspor.com/resimler/files/getegoterawitutato.pdfIn PDF document text
    • https://garyjetcenter.com/wp-content/plugins/super-forms/uploads/php/files/0039499cacf11ff1111efb0b7d4c7a77/jafinumev.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/42046770548.pdfIn PDF document text
    • http://exosportsante.fr/ckfinder/userfiles/files/lifipediremufu.pdfIn PDF document text
    • http://e-restauracion.com/app/webroot/files/uploads/files/35021256381.pdfIn PDF document text
    • https://hometeamcorp.com/images/usr/46488541475.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/posiwidorumivil.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16079f3ab985f1---37721411376.pdfIn PDF document text
    • http://mkngsp.ru/upload/files/7620791063.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085a7f167de3---dozex.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b4d7ab5137---dukutuguzijame.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091d8ea2a119---52177906449.pdfIn PDF document text
    • http://anthonyvienna.com/sites/default/files/file/80532384001.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=integrated+behavioral+health+in+primary+care+pdfPDF 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_off0001244a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1244A 18712 bytes
SHA-256: 12f75a200609a57e9dc2b20e9512f07b66320f6dcf409020f56e94aca851e58d
font_01_sfnt_off0001548f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1548F 11168 bytes
SHA-256: da81803486b6fc8037fb37494a94cf96dafc971a7b938cdba0e248ada8020102
font_02_sfnt_off00016e0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16E0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1