Malicious PDF — malware analysis report

Static analysis result for SHA-256 4201542b22159877…

MALICIOUS

PDF

83.6 KB Created: 2021-09-14 06:59:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 11da45fa77b96d01efe1c3b4b027209d SHA-1: e01b22f92cafc7851674bd28f1a58f6f66305ec8 SHA-256: 4201542b22159877116bf21a527d7a7c806fda03c5301745e81fbfd9c8206718
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The presence of multiple external URIs and link farm heuristics supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://krisoc.ru/uplcv?utm_term=scribblenauts+unlimited+apk+2020 PDF link annotation
    • https://clearpatth.com/userfiles/file/nikalituguz.pdfIn PDF document text
    • http://residenceraffaellotorino.com/userfiles/files/mokuwizizi.pdfIn PDF document text
    • http://p-jtech.com/userData/board/file/7426655472.pdfIn PDF document text
    • http://mingzhicc.com/userfiles/files/piduwow.pdfIn PDF document text
    • https://kenhquangcao.vn/uploads/files/4283589205.pdfIn PDF document text
    • http://g-shocktou.com/user_file/file/7524374575.pdfIn PDF document text
    • http://casms.org/atts/news-files/file/nawitumipes.pdfIn PDF document text
    • http://miass.realxenon.ru/uploads/files/97944082071.pdfIn PDF document text
    • http://ggmtc.net/userfiles/files/pategobunalutinomerubusa.pdfIn PDF document text
    • http://pizzeriadevita.it/userfiles/files/21971614720.pdfIn PDF document text
    • http://rapet.hu/files/5166553063.pdfIn PDF document text
    • https://adikkeempat.com/contents/files/39450778658.pdfIn PDF document text
    • https://roshnaai.com/ckfinder/userfiles/files/kititokobixamazufev.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/161367e368abf3---42342125219.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/c84a09b7d2cd278e7e258c218a4d9f2a/64556477978.pdfIn PDF document text
    • http://bigdoughpizza.com/uploads/files/13159206041.pdfIn PDF document text
    • https://ardiinerkh.mn/uploads/userfiles/files/82790449127.pdfIn PDF document text
    • http://hzbaoyan.com/images/upload/File/36994699534.pdfIn PDF document text
    • http://intelekt.biz/uploads/pages/files/84868716797.pdfIn PDF document text
    • http://xn--90afqerdlt1f.xn--p1ai/admin/ckfinder/userfiles/files/nikumanilarep.pdfIn PDF document text
    • https://sindonis.com/userfiles/file/15441880774.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/bmg51ovuonni34l3kkkj99pj64/9832450051.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_off0000e0d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D6 11204 bytes
SHA-256: 14f3c9438cec77fb2e21187bbfc1d12735ab4f97df7e8314d238cd741f7469fe
font_01_sfnt_off0000fad2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAD2 17744 bytes
SHA-256: 163a53644528de5d2b6237fde8fb39e57aafe6a4c2c6db42fe832132cdd137d7
font_02_sfnt_off000128aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1