Malicious PDF — malware analysis report

Static analysis result for SHA-256 668c5dc129b08767…

MALICIOUS

PDF

82.3 KB Created: 2021-09-05 19:28:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1cea44afee6a25260415a44d9b54dc28 SHA-1: efdce7956898b20dcf138cf377d1b78aa15d3fea SHA-256: 668c5dc129b08767957c1d28e81aa2903db0829cb3e2a20f91fa88a535f11daa
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external websites, many of which appear to be compromised WordPress installations or disposable hosting, suggesting a link farm designed to distribute malicious content. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://cructi.ru/uplcv?utm_term=chuy%E1%BB%83n+file+pdf+sang+excel+tr%E1%BB%B1c+tuy%E1%BA%BFn
    • http://modelseafarm.com/kweb/ckfinder/userfiles/files/kirub.pdf
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/940054127fbde8124ef2e00c4890fee2/gafeg.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b34a7137a84---84614128321.pdf
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/10ba24241fa8bfa4a6391187f8ed3310/67498348773.pdf
    • http://ladyqueen.it/userfiles/files/9256663591.pdf
    • https://aravlicraft.com/cmsCart//upload/file/2725323264.pdf
    • https://vidaleve.net/ckfinder/userfiles/files/22575011366.pdf
    • http://climtech.com/files/files/43782271240.pdf
    • https://globalclassic.org/wp-content/plugins/super-forms/uploads/php/files/t0ttpkn8u7gml8a55301endbsr/kozufanobe.pdf
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133d122bbf57---98254125269.pdf
    • https://daaeportrett.no/upload/file/79325581892.pdf
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/890c148af4b3a05f6f86ad9007582342/48139323430.pdf
    • http://hhsbluebirds1967.com/clients/b/b5/b592d679e9980e62d9d56be1bfb8b6b6/File/tonawasilaruj.pdf
    • http://tokyo-sanritsu.com/userfiles/file/dujemipiputulak.pdf
    • http://contextuae.com/resimler/files/satoxudasopafijerule.pdf
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607921dbe82ea---lafejaruzob.pdf
    • https://boucherienabli.com/uploads/FCK_files/file/14092296671.pdf
    • https://www.temsilcifirsatlari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c656878207---viramagufejus.pdf
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607db41caaf96---zejewulobolibisujen.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dfd413b00e5---dutodajilode.pdf
    • https://www.truegridpaver.com/wp-content/plugins/super-forms/uploads/php/files/3962fd030a3659d4b6ffda37dc11a0d8/gasuradapenir.pdf
    • http://imreelectric.sk/uploads/file/tunanijozonalodeg.pdf
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/228cb8fe60a4f8d2b517f696ba802275/sibivunufowogofobajekaxod.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cdf1.bin
9ccdac07f2338b1434b1747d0a1fa76819b257414c4b510361426113d458f5c2
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDF1 11760 bytes
font_01_sfnt_off0000e909.bin
796c6b1952e0d8e608641939972a0f66094ba0e8d756d146dec8aa221d2df0ec
pdf-font-stream PDF embedded font (sfnt) at offset 0xE909 21944 bytes
font_02_sfnt_off00012190.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12190 16792 bytes