Malicious PDF — malware analysis report

Static analysis result for SHA-256 a25d939f8e08d7db…

MALICIOUS

PDF

79.1 KB Created: 2021-09-23 17:26:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 29a3beca93be91a29efcae3bdfc177da SHA-1: 1e3e5a8271bf2f6e0c76a96ae9486e75d9b7bb9a SHA-256: a25d939f8e08d7db0bb90ccc00cf3f72342dbfb8d6ceb2c03cc7917d02aeb14d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs and link farm patterns, suggesting it is designed to redirect users to potentially harmful websites. The presence of compromised CMS upload links further supports this, as these are often abused for hosting malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://drafthe.ru/uplcv?utm_term=general+knowledge+mcqs+pdf+2019 PDF link annotation
    • http://locnuocvietmy.com/Images_upload/files/29423952039.pdfIn PDF document text
    • https://renfrewareahealthvillage.ca/ckfinder/userfiles/files/tulerajiviluzuxada.pdfIn PDF document text
    • https://zapret-rf.org/web/img/podborky/files/lizujusinevorenamikoneni.pdfIn PDF document text
    • https://hfbee.tw/upload/ckfinder_temp/files/20210903062430.pdfIn PDF document text
    • https://073741256.com/uploads/files/202109110205236872.pdfIn PDF document text
    • http://intertermo.nl/userfiles/file/36996296781.pdfIn PDF document text
    • https://kameramuzesi.com/upload/files/39039111535.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/bu1t52qclcehpjbuhc0nhrveq6/86267380522.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f22f28ebd3---namuwagekuxowono.pdfIn PDF document text
    • http://thuocnam.xyz/images/files/melozebokinunufil.pdfIn PDF document text
    • https://barcelonacentremedic.cat/files/galeria/files/wipoje.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/17630472025.pdfIn PDF document text
    • http://njbeihang.com/uploadfile/file///2021090407123974.pdfIn PDF document text
    • http://iwilldoit.ru/uploads/files/files/nobivu.pdfIn PDF document text
    • http://denge.aero/upload/files/75582071171.pdfIn PDF document text
    • http://timnhanhonline.com/upload/files/89878433459.pdfIn PDF document text
    • http://xn----7sbezcba9a5aggb3j.xn--p1ai/ckfinder/userfiles/files/tevunaxulamogejatili.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613115ecf2370---gubipokogabokupubot.pdfIn PDF document text
    • https://vibangnhadat.com/uploads/files/42928042908.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1613559c5eddac---86292454396.pdfIn PDF document text
    • http://kovofilm.cz/userfiles/file/27461158623.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_off0000ccb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCB4 11596 bytes
SHA-256: 8d7c0d55c7878b4e35c0c2b913a5015022c5630958c86e1c7e5898b69b31469c
font_01_sfnt_off0000e7e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fff5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF5 18152 bytes
SHA-256: 377db851bf8e58c71668d6d3f309a882fc1a1f2ee0d3df9696d670cbf0b8b6cf