Malicious PDF — malware analysis report

Static analysis result for SHA-256 d9209f9bae3883c8…

MALICIOUS

PDF

78.5 KB Created: 2021-09-17 12:48:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 19c2387877944ebba00ace53897b5e21 SHA-1: 4dcc3db492466f561d687286cc10ded954bde995 SHA-256: d9209f9bae3883c882f4e593915ca18a50235c234dacae6f02e11b36ef2207ff
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the numerous embedded URLs suggest the document is part of a link farm designed to manipulate search engine results or distribute further malicious content. The primary IOCs are the various unknown-reputation URLs pointing to PDF files hosted on potentially compromised or disposable domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://hygradeinsulators.com/images/uploads/file/makuguxiwiwikijuwiluvuz.pdf In PDF document text
    • https://cihangirhotel.com/upload/ckfinder/files/74011816690.pdfIn PDF document text
    • http://sinoorchids.com/image/file/11516694633.pdfIn PDF document text
    • https://pelletier-tp.fr/ckfinder/userfiles/files/matubanumenaxedij.pdfIn PDF document text
    • http://pharmabiosolutions.com/filespath/files/20210904004944.pdfIn PDF document text
    • http://encino.ilovepokebar.com/uploads/files/45536255861.pdfIn PDF document text
    • http://dangkydoanhnghiep.org/hinhanh_fckeditor/file/58917257828.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/161362592daeb9---1785179423.pdfIn PDF document text
    • http://qdsenfeng.com/data/files/50925388620.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/f67c4af27fd2a49532df9ef924ce1f9c/fekovilavodibapuxufun.pdfIn PDF document text
    • https://manualismedicina.hu/fileok/file/971747109.pdfIn PDF document text
    • http://tiga.co.th/ckfinder/userfiles/files/11721539021.pdfIn PDF document text
    • http://mariancozma.com/_user/file/dapezonewokozerobozug.pdfIn PDF document text
    • http://bulk-supplies.com/userfiles/file/remosirikizutazefokupivot.pdfIn PDF document text
    • https://mumegram.com/userfiles/file/turebejarafateletej.pdfIn PDF document text
    • http://vakantie-noordlimburg.nl/ckfinder/userfiles/files/viwedonipomojodope.pdfIn PDF document text
    • http://closehorses.com/userfiles/file/40275726026.pdfIn PDF document text
    • https://smlstripedbass.com/home/rock/public_html/ckfinder/userfiles/files/kixat.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/403f9c4ac1f10979b611e933fdb0aeb0/tupotupabusekefuwixuzufaf.pdfIn PDF document text
    • http://klm-co.ru/foto/ck/files/10170864472.pdfIn PDF document text
    • https://hmanagement.net/userfiles/file/28484704225.pdfIn PDF document text
    • http://yuanyoujie.vip/userfiles/file/mejikuk.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=72+in+1+fc+nes+apk+downloadPDF 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_off0000cd10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD10 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e522.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE522 18016 bytes
SHA-256: 0c69ee39e3541612b0692b78c6412beeda5e107395e2d34ff727a4e39baabd63
font_02_sfnt_off00011400.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11400 10720 bytes
SHA-256: 134d960649a7d05a3da5c78991b34991f0aa9ca10f16f31e83a65c163a5ea82e