Malicious PDF — malware analysis report

Static analysis result for SHA-256 25e738ad83ef2815…

MALICIOUS

PDF

94.0 KB Created: 2021-09-16 07:53:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5443d936ec5298df17bb3a1c762eb6e5 SHA-1: 3be2f482dd188e8cb87ccd7e549c7b4f1c7cd459 SHA-256: 25e738ad83ef2815911855f8f666708966060a163579e3e3c5441abae728f728
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier. Heuristics indicate it functions as a link farm, with multiple URLs pointing to compromised CMS uploads and disposable hosting domains. These links likely serve as lures for phishing attacks or to distribute further malware payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

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 http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614263dda072f---71281807167.pdf In PDF document text
    • http://vagtteam.dk/userfiles/Files/fetebidikeduripuzunow.pdfIn PDF document text
    • http://weighlessthisyear.com/ckfinder/userfiles/files/timilajelidut.pdfIn PDF document text
    • http://www.moyekolodin.com/files/70645471651.pdfIn PDF document text
    • http://zzfcw.com/file/fkimg/file/52625947722.pdfIn PDF document text
    • http://fcvperu.org/data/fcvperu/userfiles/file/zijizawidalufonepozufu.pdfIn PDF document text
    • https://tskrea.com/userfiles/file/wusimiduxufulijezu.pdfIn PDF document text
    • https://geloracinta.com/contents/files/zamawejifalawefup.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dcdd29b2e6---pejikogatuki.pdfIn PDF document text
    • http://atrsara.ir/resource/files/junowufexaw.pdfIn PDF document text
    • https://comtraining.cl/userfiles/files/59627863596.pdfIn PDF document text
    • http://nachhilfeschule.havonix.com/ckfinder/userfiles/files/57127428271.pdfIn PDF document text
    • https://workinhotel.com/upload/fckfile/memupodavanis.pdfIn PDF document text
    • https://dla-pracownika.pl/pliki_user/File/53105365299.pdfIn PDF document text
    • https://xpress2.eu/ckfinder/userfiles/files/zunolexatebidevijili.pdfIn PDF document text
    • http://opgzvh.hr/upload/file/13331603426.pdfIn PDF document text
    • http://www.cerathai.com/image/upload/File/pubupodaposegi.pdfIn PDF document text
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/48921835218.pdfIn PDF document text
    • http://pjzhengwang.com/upload/file/20210915_173330_153.pdfIn PDF document text
    • http://kvbm.org/pds/userfiles/files/risifijuwasomavetedixa.pdfIn PDF document text
    • http://minhtoangalaxyhotel.vn/app/webroot/files/ckfinder/files/66175180504.pdfIn PDF document text
    • http://kaushalacademy.org/ckfinder/userfiles/files/73911586499.pdfIn PDF document text
    • https://semangkamerah.com/contents/files/joxasulerizedadokodimuvip.pdfIn PDF document text
    • http://bielwod.com/userfiles/file/75428797592.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/406f9815ed5b2c9bf324ff750de2c335/15681400816.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=what+is+the+best+equalizer+for+androidPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140102d6352e---20443423007.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_off00010a85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A85 17808 bytes
SHA-256: 67dc0d001ec1a1f7aa6fc78ed9e8e5dbdd90b4fcd4b0bbd32ad6451bdb1880b3
font_01_sfnt_off000138c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138C2 10888 bytes
SHA-256: 165fbfb729c055c9ac0821eb10d3a112092cd18b597a379c80d61e37ab47b904
font_02_sfnt_off000151b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x151B3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1