Malicious PDF — malware analysis report

Static analysis result for SHA-256 665111ad04f74e90…

MALICIOUS

PDF

70.7 KB Created: 2021-09-20 05:27:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b0b30af8cd21a54b21c2254eb43dbe21 SHA-1: ee3dd6a850a3c425e3629402b30567190cb0b9f5 SHA-256: 665111ad04f74e90fee2e3bfe0b033d95356b3ddbfc61f83aeb21e80c9c9b188
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The PDF contains numerous embedded URLs pointing to other PDFs hosted on various websites, suggesting a link farm or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically identifies this pattern as suspicious, indicating a potential phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 https://akproauto.com/nbloom/fckuploads/file/33647739271.pdf In PDF document text
    • https://cincia.ro/ckfinder/userfiles/files/98555700766.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/fojagavonurisuzeloroz.pdfIn PDF document text
    • http://american-security-inc.com/assets/ckfinder/userfiles/files/bofaduxulaxiwopevukugoj.pdfIn PDF document text
    • http://cissi.it/userfiles/files/zegute.pdfIn PDF document text
    • https://truckforceone.eu/upload/editor/file/28716369309.pdfIn PDF document text
    • https://gedayapi.com/userfiles/file/2992760696.pdfIn PDF document text
    • https://anakaygame.net/calisma2/files/uploads/girezabog.pdfIn PDF document text
    • http://mclarenquartz.in/ci/userfiles/files/zinuxurutubiwoxopolonawu.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16144a41363520---ditilunorebozawaziz.pdfIn PDF document text
    • http://edu-family72.ru/content/images/uploads/file/noritufaweresada.pdfIn PDF document text
    • https://zoorichi.com/temp/fckeditor/file/28596486121.pdfIn PDF document text
    • https://shreenathtechnologies.com/userfiles/file/22688076067.pdfIn PDF document text
    • https://singhaniabrothersltd.com/ckeditor/ckfinder/userfiles/files/bitowemipuwadugefi.pdfIn PDF document text
    • http://anaminfo.com/attachfile/file/82728445504.pdfIn PDF document text
    • http://www.adarshvidhyasankul.org/userfilesfile/29151737983.pdfIn PDF document text
    • http://mrcubezpieczenia.pl/app/webroot/media/files/48911405017.pdfIn PDF document text
    • http://consade.com/userfiles/file/vofilegusa.pdfIn PDF document text
    • https://g4m3s-4p1-12s1.com/contents/files/lafekafadebuzinujujone.pdfIn PDF document text
    • https://nissanzorba.ro/ckeditor/ckfinder/userfiles/files/95967655522.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16133336d0484a---bipimitolotenivipapaxis.pdfIn PDF document text
    • http://ks-system.co.uk/ckfinder/userfiles/files/58096356385.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=my+hero+academia+season+5+in+english+release+datePDF 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_off0000b307.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB307 11056 bytes
SHA-256: 2f8b837843bdb6df9be6a858fe972677157d635ac8d81b4ae99256171cb899ee
font_01_sfnt_off0000cc74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC74 15836 bytes
SHA-256: dd9a5de396592c38a9aef4d0eac4546f0c58c8f12e4a1f56dfda66474b35b04f
font_02_sfnt_off0000f53c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1