Malicious PDF — malware analysis report

Static analysis result for SHA-256 a81a8cf26fcd6a7a…

MALICIOUS

PDF

85.3 KB Created: 2021-07-28 05:08:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: d92dcf902273eded8c715ed44ace7f5b SHA-1: 26b9c357ccf8b7e8e76591d52b98d5a24aaeb9fe SHA-256: a81a8cf26fcd6a7aad40f6b11f0b6aa7a1bbfadceee3349c1575ced65bb19467
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also contains numerous links to external websites, many hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to redirect users to malicious sites for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://hz-karavany.cz/ckfinder/userfiles/files/71237159470.pdf In PDF document text
    • http://vintageguitar.ru/ckfinder/userfiles/files/nogowemajerolenibonofe.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16095f35cb7243---27493031579.pdfIn PDF document text
    • https://alate.org/admin/fckeditor/editorfile/pidumazokaviwipewegodisi.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16098551a30683---20855640786.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8e0fb0c3a---darefovaleguniverox.pdfIn PDF document text
    • http://weymouthhighschool1960.com/clients/9/96/9679770cb43d952edac6f872f7aef95c/File/mubokawubepolilexikamula.pdfIn PDF document text
    • https://imad0c0.com/js/ckfinder/userfiles/files/2437567870.pdfIn PDF document text
    • http://bjzjygj.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/9014660954.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c4470052940---kupurebedapemoxusa.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609d94c656952---jupolu.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/5vdsmf28tpr8cokt1jhhdcer38/tefoworaxu.pdfIn PDF document text
    • http://wsystem.sk/userfiles/files/52951028470.pdfIn PDF document text
    • http://poorclarescork.ie/images/baladowaxada.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/tadudidafefadekizunerixu.pdfIn PDF document text
    • http://ourdesign.hk/ckfinder/userfiles/files/fumipejogi.pdfIn PDF document text
    • http://unternehmensberatung-hegenbarth.de/userfiles/file/60279982347.pdfIn PDF document text
    • http://residencecarlofelice.com/userfiles/files/zopizosedukixupatiximo.pdfIn PDF document text
    • http://workcoop.org/fckeditor/userimages/file/20210702000318.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079c81535b00---97286992248.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/csiegj15tbjh5v167i0b2hgt7u/nusumobukerebefogotatup.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608fd74fd9fc9---35115324280.pdfIn PDF document text
    • http://www.minaakshimajumdar.com/fckimages/file/xenokomufo.pdfIn PDF document text
    • http://eg-connect.com/php_codes/Scott/VieauAssociates/code/userfiles/file/12393275971.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/efdt9c2dhaj1i54m39c36v9l30/nujutezuzexifaxutixa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=mapamundi+sin+nombres+pdfPDF 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_off0000e923.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE923 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010135.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10135 17828 bytes
SHA-256: 5c01e99750674edae2bfa6b4c6957b39cb4f7951d5c95e039b29b0766c565eec
font_02_sfnt_off00012e64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E64 10748 bytes
SHA-256: e7ce49547908fed75705fccf249bca76518473b752fb8db77b01ad725ca75b34

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