Malicious PDF — malware analysis report

Static analysis result for SHA-256 3396025bf1d5e0f4…

MALICIOUS

PDF

212.7 KB Created: 2021-09-08 00:07:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 28c7db1271221996e8a98899adb09319 SHA-1: 1c98ffcca015b96ade61ccabc7dd689460aa26cf SHA-256: 3396025bf1d5e0f479c4e2d0339165e7d2475b6053472a10e79f74ead49fa243
126 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Several heuristics indicate the presence of external links, with one pointing to a compromised WordPress upload directory. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not meant for direct user consumption but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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
  • 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.
  • 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://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087f78f07022---29069279227.pdf In PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607756fabcc92---11720948429.pdfIn PDF document text
    • http://vnplastic.net/upload/files/kizabuvefinikulibedonosa.pdfIn PDF document text
    • http://lapawan15.com/shop/fck_file/file/palagefasuvoba.pdfIn PDF document text
    • http://rld-carbon.com/file/piwokupasisavijarub.pdfIn PDF document text
    • http://studiopassarotti.it/userfiles/files/duxepidelubufemuxidaxom.pdfIn PDF document text
    • https://unique-u.biz/images/uploads/file/9697598421.pdfIn PDF document text
    • http://okwmd.com/upload/fckeditor/file/mizupized.pdfIn PDF document text
    • http://wccflooring.com/userfiles/files/69687149025.pdfIn PDF document text
    • https://pingthye.com/userfiles/files/vafuvesu.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/4fa70049870ae9b555869dfc94fdcb84/koxajofem.pdfIn PDF document text
    • https://gruntbudowa.pl/files/file/65429801119.pdfIn PDF document text
    • http://www.zywawiara.pl/pliki/zuvodivagafas.pdfIn PDF document text
    • http://brightwayconsultancyservices.com/userfiles/file/19135915927.pdfIn PDF document text
    • http://grupophi.es/uploads/files/kinumogezilavosexadeno.pdfIn PDF document text
    • https://kemxoithanhhang.vn/app/webroot/files/images/pages/files/72580420695.pdfIn PDF document text
    • http://gt-outillages.fr/ressource/site-image/files/38130241357.pdfIn PDF document text
    • http://reedxtrainternational.com/uploads/pages/file/kikakuxurobijevariwemewe.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a4d187ac78c---satubapodiwikon.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c4ac9027829---torixadanagibudulofaguviv.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/7ab331294b47395157bf82850feebf09/85196720179.pdfIn PDF document text
    • http://baaningdoi.com/file_media/file_image/file/kirarukakejuzirebugapek.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=administra%C3%A7%C3%A3o+p%C3%BAblica+paludo+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_off0002d51c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2D51C 23676 bytes
SHA-256: a571c5b6b8bf50a060d3b76ecb55023aed35e851b07c8f4b2f9614c52b8982f5
font_01_sfnt_off000310d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x310D8 11448 bytes
SHA-256: aa4a283ed0ca6357710898a92c9cd05944b42e3ae742baf5f15a95d302155b00
font_02_sfnt_off00032abc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x32ABC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1