Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4c39bc70cf4511f…

MALICIOUS

PDF

82.1 KB Created: 2021-07-17 12:20:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 7e1d1c7e323be6691e22225021cecbb6 SHA-1: 42dc924d0b0827184a80c7da7294a21ffe88fbd8 SHA-256: d4c39bc70cf4511f782bdc8c386ad74085a6b24ceff98d000a107eb76d7fc5b5
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier strongly flagged this PDF as malicious, and heuristics identified it as a link farm and potentially hosting compromised CMS uploads. While no scripts were extracted, the primary attack pattern is likely to lure users into clicking these links, potentially leading to further exploitation or malware download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • 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://rkdestate.com/userfiles/file/dokugutezebo.pdf In PDF document text
    • http://berallebags.com/UploadFiles/FCKeditor/20210507034210.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/8f9ef79a40fb367f58ab2d47e72f44a5/19043004402.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1606f11840a4e5---30274143803.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/zugelebopefumumera.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160794afdecd2b---jadav.pdfIn PDF document text
    • http://kanchanaspa.com/ckfinder/userfiles/files/jimodikomenuxatu.pdfIn PDF document text
    • http://nowator-zpu.pl/userfiles/file/pekonufuvemajunodugofoz.pdfIn PDF document text
    • https://4appsoftware.it/file/69368752982.pdfIn PDF document text
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/a977fa92775eb93948bf8df339f88840/datudebas.pdfIn PDF document text
    • http://immodraft.nrw/images/architekten_agentur_images_/file/12775871729.pdfIn PDF document text
    • http://artgraf24.pl/userfiles/file/panugubexul.pdfIn PDF document text
    • http://contentworks.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606e58202f40b---giriwifuwuk.pdfIn PDF document text
    • http://e-sportis.com/images/upload/76949667840.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/def740fc18359782e6d7a7431deb88d6/gapekiwik.pdfIn PDF document text
    • https://akproauto.com/nbloom/fckuploads/file/35733538953.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/vqng6l6s13qfp86qkbr47et3g3/tiwokidipobijomi.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/438a2576c67f6271eee848e6c4f2e0c4/firobemi.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/0fdff0fc1746521eaa975f5a0c5aec8b/930343538.pdfIn PDF document text
    • http://softtox.com/new/userfiles/file/datawopanisekexakefobotef.pdfIn PDF document text
    • http://archiprojektai.lt/app/webroot/uploads/userfiles/files/puxosali.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/71i9rku35ic9h5mielivbjfqs7/sujunawut.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/guruwuwevozu.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/b3fg1kq9me8jb0itdrfpvou8s8/26712587907.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=shakespeare+novels+pdf+free+downloadPDF 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_off0000dd24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD24 10724 bytes
SHA-256: ef19960f8befea2cc817c3dea6178628a0e283f80b9b9158385cb36380db048b
font_01_sfnt_off0000f5c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C5 17248 bytes
SHA-256: a5a7648035eed0c83949750f3be81cde97531f1bdb433177b46fabddc2dac68a
font_02_sfnt_off000122c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1