Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd32590548cbba5b…

MALICIOUS

PDF

75.3 KB Created: 2021-09-11 17:46:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3b21b0161d409b40d0a75cf500480086 SHA-1: 6cf8f37b2f0b2dd5588e3f2e61fc2fe91eaa29b0 SHA-256: cd32590548cbba5b132f414ee98827aa8ba443336d9e55a425821a31f22f84e8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URIs and links to compromised WordPress upload storage, indicating a link farm designed to redirect users. The PDF structure and embedded URLs suggest it is used as a lure, likely for phishing or to download further malicious content, aligning with spearphishing attachment tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://laborke.ru/uplcv?utm_term=find+the+average+rate+of+change+of+the+function PDF link annotation
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1613433cd6dbd3---51119403769.pdfIn PDF document text
    • http://karcannakliyat.com/userfiles/file/bebozipejenegiteromu.pdfIn PDF document text
    • http://sungder.com/upload/kaxadu.pdfIn PDF document text
    • http://arcenevents.nl/site/upload/files/44408185189.pdfIn PDF document text
    • https://www.hasmow.com.au/application/third_party/ckfinder/userfiles/files/juvekawexesulazexar.pdfIn PDF document text
    • http://devison-matras.ru/upload/file/8769031363.pdfIn PDF document text
    • http://sportsbettingconsultants.net/cote_dor_import/admin/ckfinder/userfiles/files/4903365053.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/161391b12d9cc1---86177177291.pdfIn PDF document text
    • http://zafirkort.com/uploads/files/nikudevetugojilipenukox.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/161312fa30d441---23697817119.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16133b23066fc7---vodileturapefiti.pdfIn PDF document text
    • http://location-appartement-venise.com/italie_documents/files/45317109089.pdfIn PDF document text
    • https://happy-playground.gr/uploads/_uploads/files/47726025186.pdfIn PDF document text
    • http://xn--3bsx3iw22bmot.com/filespath/files/20210907063043.pdfIn PDF document text
    • http://locke-3c.tw/uploads/files/202109101807242254.pdfIn PDF document text
    • http://rhondadejean.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/45645118811.pdfIn PDF document text
    • https://myclubowners.com/userfiles/files/3506553530.pdfIn PDF document text
    • http://apismorava.eu/docs/81321559045.pdfIn PDF document text
    • http://www.egymast-segito.hu/uploaded/fck/file/64952677489.pdfIn PDF document text
    • https://dichvuhappyhouse.com/upload/files/fopuwepisa.pdfIn PDF document text
    • https://tele-video.ru/upload/files/55512412434.pdfIn PDF document text
    • http://mynigaoe.com/upload/file/20210909055401.pdfIn PDF document text
    • https://coebmsf.com/userfiles/file/76782303564.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_off0000c174.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC174 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d98b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD98B 10684 bytes
SHA-256: e090b7e2cb36daa02a8f9435915742a95e45c3b0a0074b5586e3cab1c852a0ca
font_02_sfnt_off0000f1c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1C1 17540 bytes
SHA-256: 26c7e132097c330f0cf907d2f138ca0f41f84ded05fbe41ee5414f90407f412c