Malicious PDF — malware analysis report

Static analysis result for SHA-256 c21234cbec5a7126…

MALICIOUS

PDF

89.2 KB Created: 2021-09-02 23:27:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3affb63b8f2f7935d238739d64aef5aa SHA-1: 8db396d07d65973eb8c6ff12bf4c6cb57e37bf99 SHA-256: c21234cbec5a7126ed780688173c159983518342adf029efe11db715bcc9bc4f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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 https://huntic.ru/uplcv?utm_term=chuy%E1%BB%83n+%C4%91%E1%BB%95i+%C4%91u%C3%B4i+pdf+sang+word+tr%E1%BB%B1c+tuy%E1%BA%BFn
    • https://yesilkoyluleriz.biz/resimler/files/44001466716.pdf
    • http://zeroseistudio.eu/userfiles/files/25423338749.pdf
    • https://immobilgold.com/file/12786426917.pdf
    • http://www.travelwithtaangoo.com/img/file/52777871475.pdf
    • https://burstallconrad.com/editor_files/file/sodemifetefojixowa.pdf
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/160930e7ec331d---96517780703.pdf
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae5b2572c95---mulafuwirufanugibe.pdf
    • http://moestuinwebshop.nl/userfiles/file/57302704797.pdf
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef7f053b42---lotibakebideja.pdf
    • http://seteo-dechets.com/images/file/zekeva.pdf
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/e599467efbd3467cb3744bcd3bcc1bd3/wukej.pdf
    • http://bygreenpure.com/userfiles/file/10136644499.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16073a05c1633f---zazugogaxesaworazapu.pdf
    • http://mqskin.com/luutru/files/98521590397.pdf
    • https://mcrlclient.com/ckfinder/userfiles/files/62321643759.pdf
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bc7f481af09---4543288996.pdf
    • http://luxlustry.ru/img/upload/zuloziso.pdf
    • http://consol.hu/images/uploadedimages/file/minijijixekuxuf.pdf
    • http://shihtzufurbabies.net/clients/d/d3/d383cf0c90cf2d2391705d5438694b4c/File/59173105963.pdf
    • http://www.moyekolodin.com/files/rodizavagumuropit.pdf
    • http://expresskaliski.info/file/rinoxewofuxebuxare.pdf
    • http://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/160758967df5c8---44263650089.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_off0000e469.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE469 16792 bytes
font_01_sfnt_off0000fc7b.bin
a307bd5a229d59126057826cf44467f9755a9af6f66b6a82bcbd83778c4963ec
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC7B 30652 bytes
font_02_sfnt_off000138ae.bin
b8fdf9aebcf7d64db73232b9b17317c6e5a6c071aea101c7a71da2c2baf51fa2
pdf-font-stream PDF embedded font (sfnt) at offset 0x138AE 12212 bytes