Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4b3cbcf40712597…

MALICIOUS

PDF

71.3 KB Created: 2021-10-05 13:35:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d20e971a57f62c78cd93dc676aa58c86 SHA-1: cce5bea4041ed983ef6c7c83c75fed6b788d3340 SHA-256: d4b3cbcf407125978ae115fe24929c927bc5b22cd5446ccab088d7d46ad8e132
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised or disposable hosting, indicative of a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The presence of embedded JavaScript suggests an attempt to execute malicious code or redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://infrive.ru/uplcv?utm_term=one+step+equations+with+rational+numbers
    • http://ingegnasrl.com/userfiles/files/83125029964.pdf
    • http://ros.by/ckfinder/userfiles/files/37036268906.pdf
    • http://mmbc.cz/_data/user_files/file/1808880324.pdf
    • https://horgaszvelem.hu/ckfinder/userfiles/files/karegabime.pdf
    • https://kakakmanis.com/contents/files/52473301357.pdf
    • http://aven.su/userfiles/file/fizejozobuxafoxizabilaz.pdf
    • http://sjmhospital.org/files/js/ckfinder/userfiles/files/wikebesuxumixade.pdf
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1614b426223553---76071240283.pdf
    • https://ruta.hu/ckfinder/userfiles/files/zurimejusagapibifurum.pdf
    • http://maiodi.com/userfiles/files/7297473531.pdf
    • http://ourconn.com/userfiles/file/202109130038174968.pdf
    • http://www.rajpuc.pl/pics/file/vuvaradel.pdf
    • https://mimpiindah1.com/contents/files/12885373803.pdf
    • http://farashimirooz.com/files/6310621084.pdf
    • http://infas.cz/images/wiswig/file/51822806846.pdf
    • http://nessium.fr/userfiles/file/38353780091.pdf
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/c4c8364bb24d959a4812c590c219c7e2/57303622907.pdf
    • http://vaonhaphatphap.com/images/uploads/files/bokubazewoximirapuloras.pdf
    • http://cloudinfo01.smartevolve.com/images/ckeditor/files/72509116400.pdf
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1614b075975434---gumajapapupowore.pdf
    • https://korvioinfotech.com/ckfinder/userfiles/files/1159542733.pdf
    • http://rentaruedas.com/files/others/70227819233.pdf
    • http://jj-metals.com/userfiles/file/2021090801334373499.pdf
    • 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_off0000b3c9.bin
5840b113ad1810aa2334376043bfd793ecb37ad93efb54d0b392ecaabf51e633
pdf-font-stream PDF embedded font (sfnt) at offset 0xB3C9 11012 bytes
font_01_sfnt_off0000cd11.bin
a228669cad54cbb36afdd0731b813857acf474154adce842e1f9519d8d4971f6
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD11 16464 bytes
font_02_sfnt_off0000f77e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF77E 16792 bytes