Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b5c88533e69fb06…

MALICIOUS

PDF

72.4 KB Created: 2021-10-03 11:26:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 02243fa07dc5a3f89cb9bc0038b88ead SHA-1: 6f78e61a561941190b38141ccef75ba3cc88120b SHA-256: 6b5c88533e69fb0693891002077619a002913299ff1dca3b9cf6cbe24728d0ae
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute traffic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9885

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 http://nzozkrowodrza.pl/uploads/editor/file/15988714619.pdf In PDF document text
    • http://agarimo.com/archivos/archivos/xidori.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614f13ecd5c76---mesewabofi.pdfIn PDF document text
    • http://megaprestige.ru/uploads/files/53844628040.pdfIn PDF document text
    • http://lindendirect.com/ckfinder/userfiles/files/midewezekata.pdfIn PDF document text
    • http://atsrealtyvietnam.com/upload/files/ninukatededidajozi.pdfIn PDF document text
    • https://schodyperfekt.pl/user_upload/file/59434988578.pdfIn PDF document text
    • https://hunglivet.com/uploads/files/202109131747041066.pdfIn PDF document text
    • http://baraanduliaptti.org/userfiles/file/surozarug.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/91548838071d20c8ff9b185cae557875/11438486423.pdfIn PDF document text
    • http://www.motionmantra.com/userfiles/files/kinamemofejimevanobuv.pdfIn PDF document text
    • http://ls12368.com/userfiles/file/53537769974.pdfIn PDF document text
    • http://epoptavky.com/is/images/FCKeditor/File/soxitigilizilomapa.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f1f971964---21013994488.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/zodogumowovalipev.pdfIn PDF document text
    • http://pusheng168.com/uploadfiles/20210904192241.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1614da377bcfe1---32033068618.pdfIn PDF document text
    • http://diskacme.dk/images/upload/file/nabejazuzudomazetid.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/28714879948.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615367421858f---fuluneno.pdfIn PDF document text
    • http://kientrucnhacuagio.com/upload/files/45710737992.pdfIn PDF document text
    • http://sicilalluminio.it/userfiles/files/pexor.pdfIn PDF document text
    • https://thuhuonglacquer.com/uploads/news_file/67927677360.pdfIn PDF document text
    • http://dpsnowodworze.pl/userfiles/file/67716448028.pdfIn PDF document text
    • http://bapassamarinda.id/assets/ckfinder/core/connector/php/uploads/files/45057124864.pdfIn PDF document text
    • http://afro-safari.com/upload/files/motibudu.pdfIn PDF document text
    • https://interangkorcondominium.com/userfiles/file/monuxuzumozadajor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=japanese+chin+costPDF 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_off0000b62f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB62F 17880 bytes
SHA-256: 3eec69da4565af8c9757c277037c20ecf434c686dc4d6d8b2e3cab85a16aa8b7
font_01_sfnt_off0000e4a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fcb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCB9 10316 bytes
SHA-256: f6188533c4d4d4fefab0a95aad8b9986b755902595b88961ac1da7c0c1883507