Malicious PDF — malware analysis report

Static analysis result for SHA-256 749fc63e73e9af50…

MALICIOUS

PDF

85.8 KB Created: 2021-09-20 09:54:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3bbd7ab2d0aa228cdd6f61584abe9648 SHA-1: 1850e391c5160c6d5ec8d6185b9fa4270720edb0 SHA-256: 749fc63e73e9af50e13d32fc8e77ece126bd5d3597314159160d408b9d7dd314
156 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to multiple external URLs, many of which are hosted on compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or redirecting users to malicious content. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/0b5445e56c388d7f248c9225066fc247/30146309527.pdf In PDF document text
    • http://sdes.in/uploads/murixizavikuxurufurozowu.pdfIn PDF document text
    • https://diamond-marketing.cz/soubory/68721230182.pdfIn PDF document text
    • http://jiuxingchaoshi.com/uploads/file/090419202985.pdfIn PDF document text
    • http://rybarict.cz/webpagebuilder/ckfinder/userfiles/files/24760399728.pdfIn PDF document text
    • http://khaskhaan.mn/uploads/userfiles/files/povaduwanivomipowuvuge.pdfIn PDF document text
    • http://cuacuonbinhduong.com/upload/files/21466437984.pdfIn PDF document text
    • https://samngaimarble.com/html_upload/file/xofoxowizokajididedevumin.pdfIn PDF document text
    • http://pmrs.ps/userfiles/file/lozowadit.pdfIn PDF document text
    • http://skia22.ru/pic/file/95989247512.pdfIn PDF document text
    • http://oio.cn/uploadfiles/files/8995464510.pdfIn PDF document text
    • http://www.shjkyq.com/up_files/FCK/file/19963587927.pdfIn PDF document text
    • http://goforthegreengolfpools.com/userfiles/file/zupilinir.pdfIn PDF document text
    • http://gallery4walls.com/upload/editer/file/famena.pdfIn PDF document text
    • http://biblioteka-belzec.pl/upload/files/91691828298.pdfIn PDF document text
    • https://ferest.ro/imagini_ws/5232917556.pdfIn PDF document text
    • https://nurdagihaber.com/resimler/files/taralaki.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/2e1f966f8b145bd85b001630b5806494/4262646881.pdfIn PDF document text
    • http://imaginove.eu/data/Files/72026855069.pdfIn PDF document text
    • https://ratosatu.com/contents/files/guguvokusinafolijokigepew.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/9408355318.pdfIn PDF document text
    • https://morabia.fi/images/file/zipenopawuxitup.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d1014d8daf---tajanef.pdfIn PDF document text
    • http://fatfailogistics.com/fckeditor/files/file/vovofolo.pdfIn PDF document text
    • https://sieuthimayphat.com/ckfinder/userfiles/files/39009378623.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/9ucjn4bli3h786vcbf1dr9pqd7/74291121804.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=fundamentals+of+thermodynamics+9th+edition+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_off0000e960.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE960 11244 bytes
SHA-256: 12f6cc7d0cc0fdea82ff212da000dbae6cf7e7262f6497884b1c92bf9ac18c2b
font_01_sfnt_off00010392.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10392 17468 bytes
SHA-256: 6fadc1fd36d9c6fec4d78c33f432deff7081be1ab68d0b7ae100b23e2b1b0966
font_02_sfnt_off000130fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1