Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2a88bfa3d77bf0f…

MALICIOUS

PDF

76.6 KB Created: 2021-09-29 11:58:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 61a648a6e470d027d43466208fc8c08d SHA-1: 84cacffd3a73674cebc948199f18cc795c709ad3 SHA-256: b2a88bfa3d77bf0f5d744d942d74bf05fc84941c961aa0b372f7d7540d8d6e28
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest a phishing or malware distribution intent. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • 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.
  • 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://catamma.ru/uplcv?utm_term=omega+ruby+apk
    • http://bkht.vn/userfiles/file/nasipidegovag.pdf
    • http://www.dean-cpa.com/files/adminpic/file/pukawaf.pdf
    • http://eptesteplelek.com/uploads/file/26033871875.pdf
    • https://webmakler.org/userfiles/file/josexeguvigufikikotatola.pdf
    • http://dobre-jaja.com/Upload/file/bexalemogiperepuliwes.pdf
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/1c9d07c9f23559ec49a644cc3d4e5d85/49921343163.pdf
    • http://lncxjzxxw.com/upload_fck/file/2021-9-22/20210922160500854375.pdf
    • http://bienbao.org/uploads/files/wafigeziwuvixuforuj.pdf
    • https://kaptenhoki.net/contents/files/5272610703.pdf
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c65f86f3cc---wamomitamuguzufogazufufo.pdf
    • https://strongpointmarketing.net/userfiles/file/74843593393.pdf
    • https://noble-program.site/js/ckfinder/userfiles/files/12055295617.pdf
    • https://trompis-tondschungel.de/userfiles/file/givuvab.pdf
    • http://solee56.com/ckfinder/userfiles/files/1410586083.pdf
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613393f909384---62509622950.pdf
    • http://alarm.pl/userfiles/file/kulomus.pdf
    • http://perfect-aerosol.eu/userfiles/file/74129669709.pdf
    • https://emailchopper.rockeit.com/userfiles/file/56477596905.pdf
    • http://theorientgarden.iorderfoods.com/uploads/files/56332915074.pdf
    • http://raylutickenterprises.com/userfiles/files/zowenozipar.pdf
    • https://sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/16144dd0deca41---bimopasumelipe.pdf
    • https://sacc-la-chaux-de-fonds.ch/fichiers/file/tomebetabibudofo.pdf
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/161444d55e3833---48496521401.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_off0000c1a6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC1A6 16792 bytes
font_01_sfnt_off0000d9bd.bin
90d6e308db635cd6f3c3a7672d6222a61ddf2dcb99cb3fbce801c211a02abe5e
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9BD 10436 bytes
font_02_sfnt_off0000f144.bin
beb294befd4a66f832700e4675294449dc1d11a3417d7283db43b5d8d715d5a6
pdf-font-stream PDF embedded font (sfnt) at offset 0xF144 19744 bytes