Malicious PDF — malware analysis report

Static analysis result for SHA-256 20cb1b1fa313a26c…

MALICIOUS

PDF

76.4 KB Created: 2021-09-21 08:52:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 835336d40298b5570e535e96b6ebb06a SHA-1: 9c80c0beaf54c59071198b5ec9d3540b1a4d17a4 SHA-256: 20cb1b1fa313a26c81a25c27d5549c0fb2f4c97ab55f8c9e524c68ff24cf18e8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress upload storage and other disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the PDF structure itself is used to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://casaalu.com/luutru/files/19298133862.pdf In PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145c792347f6---pujitizaliditepot.pdfIn PDF document text
    • http://xszhuhai.com/uploadfiles/files/revakiwiwida.pdfIn PDF document text
    • http://centreforeffectivecoaching.com/media/file/jobidu.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141c1433c524---82011578594.pdfIn PDF document text
    • https://nabsangram.com/userfiles/file/9774531553.pdfIn PDF document text
    • http://puzynowska-kancelaria.com/userfiles/file/xodazomudugoka.pdfIn PDF document text
    • http://baove247.org/upload/files/sibisutopitoge.pdfIn PDF document text
    • http://slavutich-media.ru/userfiles/file/fivifux.pdfIn PDF document text
    • http://darec.sk/files/files/ratufatir.pdfIn PDF document text
    • https://ahha.az/userfiles/file/kilaxawib.pdfIn PDF document text
    • http://dietaltop.com/userfiles/files/54088374407.pdfIn PDF document text
    • http://izumrud38.com/ckfinder/userfiles/files/dasuwuzifox.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16133cf9217a0b---raviwarifeweg.pdfIn PDF document text
    • http://ongxoanhdpe.vn/upload/files/dolevuxorujozemugimo.pdfIn PDF document text
    • http://constantemails.com/userfiles/file/1631321903miletizoluzup.pdfIn PDF document text
    • http://otestmanager.org/club/data/userfiles/file/20210906222315.pdfIn PDF document text
    • http://chroscina.com/userfiles/file/sibizimirosanuxuwa.pdfIn PDF document text
    • http://businesslegalgroup.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wiselipijesixu.pdfIn PDF document text
    • https://afgventuregroup.com/cfiles/file/42254138849.pdfIn PDF document text
    • http://futimisdev.com/userfiles/file/nakegazofolarugujakonab.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/16138751d54f38---92276707.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=hungama+songs+pkPDF 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_off0000c3f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3F6 19016 bytes
SHA-256: 931c1cbfae32c96214452dfb68993b140d33841b958c39b79e4c66757bcd5691
font_01_sfnt_off0000f529.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF529 10312 bytes
SHA-256: 5e7bfdceaa74ec3935cc851d1c92e29a7783964a39166fe2e270c521fdbef5cb
font_02_sfnt_off00010c54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C54 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1