Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac93dc28beee362a…

MALICIOUS

PDF

79.6 KB Created: 2021-09-19 23:11:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 24a7f88bfd23686e4549d6d4d5c322f2 SHA-1: 162add1556268cc3deb0e850fa90295df9a6a6ec SHA-256: ac93dc28beee362a9fe6f21b3f375bfc506e28390e5e269df5c3444096a3e0e0
156 Risk Score

Malware Insights

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

This PDF was flagged as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body is unreadable, but the heuristic firings strongly suggest a malicious intent to exploit users via these external links.

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://krantiservice.com/ckfinder/userfiles/files/12284200148.pdf In PDF document text
    • http://propertiesforrent.com/userfiles/file///beveponeraguso.pdfIn PDF document text
    • http://razaviota.ir/basefile/razaviotair/files/35601404120.pdfIn PDF document text
    • http://thaoduocquyhiem.com/userfiles/image/file/likikuk.pdfIn PDF document text
    • http://hferrynetworks.com/FileData/ckfinder/files/20210917_B0F448F4B905ABB5.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/d013c92ffb3dfbafd41d0470024580ef/petanijirigapineziluwu.pdfIn PDF document text
    • https://shreenatharcade.com/userfiles/file/60079045220.pdfIn PDF document text
    • http://saopauloairporttransfers.com/ckfinder/userfiles/files/bajoxivujamizumivuwakapu.pdfIn PDF document text
    • http://www.w.radeton.cz/ckfinder/userfiles/files/23368985079.pdfIn PDF document text
    • http://eichler-kammerer.de/59385759016.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16140063844bdc---6493304513.pdfIn PDF document text
    • http://www.musicboxpiano.com/contentfiles/7765305140.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/731976919.pdfIn PDF document text
    • http://abpaluso.com/upload/file/mumitik.pdfIn PDF document text
    • https://www.utn.ac.cr/sites/default/files/files/55115181099.pdfIn PDF document text
    • http://www.sm.ac.th/ckfinder/userfiles/files/38836936248.pdfIn PDF document text
    • https://iqrainternationalschool.org/_assets/files/tunikag.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161425db9c1020---72736711190.pdfIn PDF document text
    • http://topp.pl/_topp/file/33354134884.pdfIn PDF document text
    • https://stomatoloska-ordinacija-rijeka.com/files/dorozediliv.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141938b3bcd8---pavuzapo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=average+rate+of+change+of+polynomialsPDF 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_off0000cf5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF5E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e770.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE770 18524 bytes
SHA-256: 8c4e4e27bff1676b6b0477e0c6c48c676aa024c6c3f48d46369b93848824de8e
font_02_sfnt_off000117a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117A0 11088 bytes
SHA-256: 3eb6dadf4caef9d80149fea98547b77169a5f4f2ddd8ac637832506c1d5851b3