Malicious PDF — malware analysis report

Static analysis result for SHA-256 cef5b3d58fa0ebb8…

MALICIOUS

PDF

79.7 KB Created: 2021-09-17 15:01:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8ee234fefa26c8e22d936e25b8e86aad SHA-1: 633c82ffc8ef1f6f4997712b35c0dd46e7ddfc3f SHA-256: cef5b3d58fa0ebb8238d0af0a8e492d739e8cbf8507637d21f6f1bd54f31c278
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which are part of a link farm hosted on disposable or compromised domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware hosting sites. The embedded JavaScript could be used to further obfuscate the malicious redirection or exploit PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://medvor.ru/uplcv?utm_term=can+you+connect+ps4+controller+to+android+phone
    • http://thaisomboonautopart.com/userfiles/files/44614282835.pdf
    • http://yourhandmadeitems.com/userfiles/file/turunukowikoji.pdf
    • http://kovofilm.cz/userfiles/file/variluzurunajes.pdf
    • https://wrd13.com/force/file/78481893355.pdf
    • http://agavietnam.com/img/files/keraraxugavabifil.pdf
    • https://netwindowvn.com/uploads/userfiles/file/ludemirudugolafama.pdf
    • http://4998horo.gmmwireless.com/contents/files/82835317111.pdf
    • http://regalmotors-jp.com/js/upload/files/pakupofagalobitikejofusak.pdf
    • https://imaggu.com/ci/userfiles/files/4999935541.pdf
    • http://itcck.org/upload/editor/file/59822974295.pdf
    • https://okazdedziecko.pl/_files/Media/file/jasusovinezaxegejanexenum.pdf
    • https://mimpishio1bet.com/contents/files/kilimivurog.pdf
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613edca40af33---67435485179.pdf
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bad372a79f---dutegezefajavazinofomuk.pdf
    • http://ortosprendimai.lt/userfiles/file/70192718238.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/161329034d1a05---98051118667.pdf
    • http://vipacademy.org/userfiles/file/12538018099.pdf
    • https://calienglish.com/ckfinder/images_store/files/kofujotipunufajaxaso.pdf
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16142498328b57---39691672417.pdf
    • https://ladachess.ru/userfiles/file/78757242127.pdf
    • http://didopack.com/files/83416819921.pdf
    • http://bloodfaces.de/attachment/file/paxexiwam.pdf
    • https://butyfarm.mm520.net/userfiles/files/nojumina.pdf
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/6b45d25b1eb2790c9c6a19afb6eb78e9/momizewixis.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_off0000d364.bin
ad26dac9b1a513dbd4f521f82d1c4a04d2dc2bb8e1324226577072ffe10c4fe9
pdf-font-stream PDF embedded font (sfnt) at offset 0xD364 10932 bytes
font_01_sfnt_off0000ecbe.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xECBE 16792 bytes
font_02_sfnt_off000104d0.bin
76812a94b412d664925526f1139079e30ddfd4636a100bd6b73b413250fed4e0
pdf-font-stream PDF embedded font (sfnt) at offset 0x104D0 16740 bytes