Malicious PDF — malware analysis report

Static analysis result for SHA-256 bff8fbab7b7ac9bc…

MALICIOUS

PDF

81.2 KB Created: 2021-09-09 23:47:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 96738c82940e1d6b652c3e73fd1e3951 SHA-1: 7ba3235a8e664015c758199ec270315a092f6c63 SHA-256: bff8fbab7b7ac9bc49a845acedbe4d4b4d4180f79cb75943ddf968ac9d5627f5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many pointing to compromised WordPress sites, and a link farm pattern suggesting a phishing or malware distribution lure. The presence of external URI heuristics and the ML_NYX_PDF_MALICIOUS firing strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://smidgel.ru/uplcv?utm_term=sonic+games+unblocked PDF link annotation
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613289c292f52---39280698929.pdfIn PDF document text
    • http://xn--90aoa5aj.xn--p1ai/ckfinder/userfiles/files/nenol.pdfIn PDF document text
    • http://zjhywt.com/images/upload/File/zemagidojovazikus.pdfIn PDF document text
    • https://ystechpro.com/nbloom/fckuploads/file/47510322830.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161321a2f0019c---99825421743.pdfIn PDF document text
    • http://dansecyr.ca/pdf/file/wipijuliliwufupor.pdfIn PDF document text
    • https://www.hermanosvalerorecio.com/ckfinder/userfiles/files/zozusaweroxenozuvelavuvu.pdfIn PDF document text
    • https://edouardweil.com/userfiles/file/vupowuteborarevuxisedotox.pdfIn PDF document text
    • http://vers-ma.de/userfiles/file/noranigipo.pdfIn PDF document text
    • http://cnokorea.com/userfiles/file/63057680400.pdfIn PDF document text
    • http://myatkinsonfamily.com/userimages/tijamud.pdfIn PDF document text
    • http://www.heksan.com.pl/file/forur.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16138f9ab1722c---1639760901.pdfIn PDF document text
    • http://keitbg.com/images/files/fujibugaparumetivig.pdfIn PDF document text
    • http://oishisushigd.com/uploads/files/tiranuwojizaxir.pdfIn PDF document text
    • https://cvsc.co/userfiles/file/48974036488.pdfIn PDF document text
    • https://aimtronu.org/userfiles/file/62136483154.pdfIn PDF document text
    • http://garant-fond.ru/ckeditor/ckfinder/userfiles/Images/files/luxufil.pdfIn PDF document text
    • http://hyundaidongdo3s.com/images/files/ziliwareduz.pdfIn PDF document text
    • http://lindseyderence.com/userfiles/files/56244534397.pdfIn PDF document text
    • http://fullx.net/files/derejigabupef.pdfIn PDF document text
    • https://wietsevoermans.nl/ckfinder/userfiles/files/daxifirimopo.pdfIn PDF document text
    • https://associazionemusicaviva.it/uploads/file/17432610098.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_off0000d7ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f006.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF006 10920 bytes
SHA-256: 8a717643a377250630d9c25c1b99aba1d94e480a2c7fa31eeac4fb68863dbdd9
font_02_sfnt_off0001090e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1090E 17888 bytes
SHA-256: f1660943e0e67d1cf9ab627894ed238217491397124c60f72f7a9f968bd96559