Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc24606f4ada82d4…

MALICIOUS

PDF

70.2 KB Created: 2021-09-14 03:49:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ab0406ac948e31e2a46aff175216f809 SHA-1: 4c12dbf118a2811f946e0da6d49a44598baba118 SHA-256: dc24606f4ada82d4236bb9e251a25a915e40ec6d8544d440657c855f902fcac2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The sample was identified as malicious by ML classifiers and ClamAV, with a high heuristic score for being a link farm on disposable hosting. The PDF contains numerous embedded URLs pointing to various PDF files, suggesting a tactic to manipulate search engine results or distribute further malicious content. While no scripts were explicitly extracted, the nature of the embedded URLs and the PDF structure strongly implies an attempt to redirect users to malicious sites, aligning with spearphishing and exploitation techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://younewstoday.com/task/userimages/file/68907891246.pdf In PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/budujojimaliw.pdfIn PDF document text
    • http://mtcnx.com/upload/fckimagesfile/62276984400.pdfIn PDF document text
    • http://ipceurope.com/assets/file/93161442999.pdfIn PDF document text
    • http://www.oomewatersport.nl/upload/files/zukagotetuwevuwip.pdfIn PDF document text
    • http://www.huescalamagiaenfotos.com/userfiles/files/tematikig.pdfIn PDF document text
    • https://askisan.com/upload/ckfinder/files/23994921234.pdfIn PDF document text
    • http://duda-tech.pl/dudatech/upload/file/sotezuxoge.pdfIn PDF document text
    • http://saraya-shop.ru/upload/files/66477871395.pdfIn PDF document text
    • http://www.oomewatersport.nl/upload/files/revad.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/73917429287.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/28101372281.pdfIn PDF document text
    • http://mikailang.net/userfiles/file/20210906003826_732657658.pdfIn PDF document text
    • https://jin-ji.com/upload/files/98202665180.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/2p86ekq80g6tke0p4koemp0hev/xaxevifazakogatake.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d0db0a06ba---fewumer.pdfIn PDF document text
    • http://omni-links.com/images/blog/file/xijuleguxafamawupu.pdfIn PDF document text
    • http://lineshare.net/upload/files/20210913210225.pdfIn PDF document text
    • http://kasaitogo.com/uploads/files/vimobeliwaj.pdfIn PDF document text
    • https://nonbodepsg.com/uploads/files/22787262966.pdfIn PDF document text
    • http://dissanna.com/temp/fckeditor/file/47838848509.pdfIn PDF document text
    • http://hanauhrova.cz/files/71996108054.pdfIn PDF document text
    • http://kooijobs.in/ckfinder/userfiles/files/46031291981.pdfIn PDF document text
    • http://jujucuisine.com/userfiles/file/90523144576.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=how+to+download+free+fire+directly+in+sd+cardPDF 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_off0000b0a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c8ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8BA 16516 bytes
SHA-256: a31fc05da335d5a3314800de66565d70f0d96503ca59112575ca48f400262fb9
font_02_sfnt_off0000f2b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2B0 10660 bytes
SHA-256: 31628b0ec025bf2389415fe2f628eba441805ee83fde679bc8f041bf9f42669a