Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6b7918a1bf5c891…

MALICIOUS

PDF

81.1 KB Created: 2021-09-19 18:51:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 235cb68b793aa11056c6727179344671 SHA-1: 313d5d3ca98f15f7de8fe6a263373256367dbcdc SHA-256: f6b7918a1bf5c8916db31eefe5b822ec87a74ee216961950c96de32681199e5d
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm. Multiple embedded URLs point to various domains, many of which are unknown or potentially disposable, suggesting a phishing or malware distribution scheme. The document body is unreadable, but the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests the intent is to redirect users to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://stlukesfp.org/ckfinder/userfiles/files/jizikipiwiwegenajobup.pdf In PDF document text
    • http://hiredriver.com/uploads/assets/files/todetiziximaru.pdfIn PDF document text
    • http://gjbbang.com/userData/board/file/kozapeg.pdfIn PDF document text
    • http://pcccphucvinh.com/upload/files/59889267005.pdfIn PDF document text
    • http://salt17.com/userfiles/files/silotesedovenuzekura.pdfIn PDF document text
    • http://truhlarstvi-strakonice.cz/files/file/79905859358.pdfIn PDF document text
    • http://maysoi.com/hinhanh_fckeditor/file/nenefulasibij.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/161369f9652890---gatonut.pdfIn PDF document text
    • http://yuli-china.ru/d/files/40390736421.pdfIn PDF document text
    • http://gestaocipa.com/public_html/Imagens/file/24321985238.pdfIn PDF document text
    • https://urology-andrology.com/userfiles/file/wabitirexokiradikela.pdfIn PDF document text
    • http://xn--66-6kc8bfmkmjd.xn--p1ai/admin/ckfinder/userfiles/files/82177372130.pdfIn PDF document text
    • http://ibshop.gr/uploads/_uploads/files/6293103609.pdfIn PDF document text
    • https://sentinels.ro/userfiles/file/notivemubenegemebama.pdfIn PDF document text
    • http://irfanmakina.com/depo/sayfaresim/file/zuvimikikake.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161390e87809a5---65064041611.pdfIn PDF document text
    • http://realtor-madrid.com/uploades/fckeditorfile/5672528321.pdfIn PDF document text
    • http://gjbbang.com/userData/board/file/xemikepurerorowazu.pdfIn PDF document text
    • http://sanzmendia.com/userfiles/files/91806551856.pdfIn PDF document text
    • http://qianxi.cn/filespath/files/20210903102846.pdfIn PDF document text
    • https://ngoctraithaibinhduong.com/uploads/news_file/5040442601.pdfIn PDF document text
    • http://inphuduong.vn/upload/files/mepebodoto.pdfIn PDF document text
    • https://groupunsur4.com/contents/files/97173233950.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=off+the+road+gamePDF 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_off0000db03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f31a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF31A 10416 bytes
SHA-256: 86955b06b944acdf96406a7db1db7f4af5e57e9cc1a2589d2a086f991141eb59
font_02_sfnt_off00010a81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A81 17324 bytes
SHA-256: 7c2e1ab1582b49922528f0dbd633eb2155a335581b746f3cc92bb89f2c3b3cb2