Malicious PDF — malware analysis report

Static analysis result for SHA-256 398c3ee91728dd98…

MALICIOUS

PDF

81.1 KB Created: 2021-09-20 03:28:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3e16de14d23556d1ffb1f340d41ee064 SHA-1: eb870d893e5c2f11c2f6479820d39f62cd438fbf SHA-256: 398c3ee91728dd984642e7476636cc63f6b64a7d10ffc202ccce7b94a4f24402
156 Risk Score

Malware Insights

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

The PDF was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised WordPress upload storage and other potentially disposable hosting. The document body is heavily obfuscated and does not provide direct user-facing content, reinforcing the interpretation that its primary purpose is to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://moveo-sport.pl/userfiles/file/74730860401.pdf
    • http://simkoongschool.com/uploads/editer/files/42538560651.pdf
    • http://olynskiconstruction.com/pics/file/sinede.pdf
    • http://nawoo.net/userData/board/file/88241516343.pdf
    • https://larioenergy.net/uploads/file/kazixeloropunerobitumulo.pdf
    • http://engcaphone.com/_UploadFile/Images/file/dexometegof.pdf
    • http://hoangnampte.vn/quangbasanpham/app/webroot/upload/image/files/zidegipixorufijudivi.pdf
    • https://dienhoanghean.com/upload/ck/files/25549121522.pdf
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/1613e478bd2541---11901171728.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613864b2745f5---tigipixonekoti.pdf
    • https://parklanehotel.asia/userfiles/file/16051880236.pdf
    • https://emmaushuis.org/pages/51059368287.pdf
    • http://cungcapbaoduongcuanhatban.com/upload/files/refagawipapukup.pdf
    • http://innova-perila.ru/upload/files/xulevixokatebofojexifaj.pdf
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/d1902a71a79d683844e70c4e65c05323/94149593610.pdf
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/laturibevorati.pdf
    • http://macro-e.com/app/webroot/userfiles/files/fapoz.pdf
    • https://kaxtongroup.com/home5/maxconne/public_html/kaxtongroup/assets/images/newspostimages/files/zupurematejaxufinagef.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16139d30191b90---fipezojizivazuzikogu.pdf
    • https://walkandsmile.com/userfiles/file/nowubebekerodujajozulo.pdf
    • http://www.keizerco.nl/userFiles/file/16539409422.pdf
    • http://damosushipleasanthill.com/uploads/files/85332706299.pdf
    • http://profstil.az/userfiles/file/linarawepufofa.pdf
    • http://csc-vietnam.vn/uploads/userfiles/file/kinuwapesinagokelo.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=hg+ss+safari+zone
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d7cf.bin
e31867ef8db0a61ca5e0d8a02681acd7d98b8d4af1f489895e3ddfc86ba3ee03
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7CF 18332 bytes
font_01_sfnt_off000107b5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x107B5 16792 bytes
font_02_sfnt_off00011fcc.bin
358bec184a69fbe24df628e1f7042493140e5ce39d53a5919fd2624fd0a32e3a
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FCC 10296 bytes