Malicious PDF — malware analysis report

Static analysis result for SHA-256 b24665f50cae21fb…

MALICIOUS

PDF

93.3 KB Created: 2021-09-14 08:46:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 29381737214bd02b3820b32f36d91faf SHA-1: da1ed3081fa99b8561b7810f3c6b5aa394adff07 SHA-256: b24665f50cae21fba984718301550364c44345c3ba9ab1f259b43df3274c1064
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct content-based clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://crewmak.ru/uplcv?utm_term=minecraft+download+android PDF link annotation
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/pqqcrdome082qmfuuob15nmoq1/16251957939.pdfIn PDF document text
    • http://s4l.vn/storage/ckfinder/files/91121449706.pdfIn PDF document text
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/84379592589.pdfIn PDF document text
    • http://oawebserver.com/piceditor/file/11108903386.pdfIn PDF document text
    • http://studiomalpocher.it/userfiles/files/4106556.pdfIn PDF document text
    • https://poldercuptrofee.nl/site/admin/ckfinder/userfilesfiles/depubawupatetaputugomu.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/jusovumezajo.pdfIn PDF document text
    • http://fs-select.com/images/blog/file/fuwugu.pdfIn PDF document text
    • http://www.andreapondika.cz/file/16362972144.pdfIn PDF document text
    • http://flirdining.com/uploads/files/texazusapaselututoba.pdfIn PDF document text
    • http://tobn56.com/UpFiles/file/nonefofizamawunajopi.pdfIn PDF document text
    • http://araonline.hu/uploads/file/13879585797.pdfIn PDF document text
    • http://zamgph.com/FCKeditor/editor/filemanager/connectors/php/uploads/file/121343448452.pdfIn PDF document text
    • http://salwex.hu/file/bokoli.pdfIn PDF document text
    • http://yksskj.com/ckfinder/userfiles/files/93822400599.pdfIn PDF document text
    • https://happy-playground.gr/uploads/_uploads/files/47726025186.pdfIn PDF document text
    • http://adas-muko.pl/photo/file/44371196335.pdfIn PDF document text
    • https://dnm.tw/uploads/files/202109120843289459.pdfIn PDF document text
    • http://djk-winkel.de/images/uploads/file/55118505771.pdfIn PDF document text
    • http://cortabellanews.com/userimages/tatevezigenotojanil.pdfIn PDF document text
    • http://midesignvn.com/uploads/files/41110289564.pdfIn PDF document text
    • http://maxbrio.kr/files/files/zafagejofijososunosotizo.pdfIn PDF document text
    • http://tythb.cn/uploadfile/files/10634138519.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613406fdd6acb---4825967550.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_off0000fffb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFFB 10380 bytes
SHA-256: 0a34e72afd48535dae6081431935dc5363a83bbd7a33300c73a5d04eb93a2a06
font_01_sfnt_off000117a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117A1 21052 bytes
SHA-256: 2ef174acd2cbe80f5fcd20b2ad7a23265ec1db59febccd56d8a7601fb236802e
font_02_sfnt_off00014f89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F89 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1