Malicious PDF — malware analysis report

Static analysis result for SHA-256 4abf8c1ee766d56d…

MALICIOUS

PDF

75.9 KB Created: 2021-09-21 05:12:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 542db0f2b5311d9ba141f24ac1980bd4 SHA-1: e8246b9769643787923cd112352880e8b613077a SHA-256: 4abf8c1ee766d56d3076adb9613b5ceb8f2d3b163ba1bc8a67fd07ede9eb6da2
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier strongly indicated maliciousness, and the presence of an embedded JavaScript stream further supports malicious intent, likely for initial access via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • 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://garglob.ru/uplcv?utm_term=super+smash+bros+2+apk PDF link annotation
    • https://danielfelber.ch/userfiles/file/45715175768.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ffb9d7d8e3---sagub.pdfIn PDF document text
    • http://dailythang.com/userfiles/files/kanujoxajapigezok.pdfIn PDF document text
    • https://magnettoptan.com/upload/ckfinder/files/28408326630.pdfIn PDF document text
    • http://opuspointpartner.com/ckfinder/userfiles/files/rumupasi.pdfIn PDF document text
    • https://nuttydog.hu/ckfinder/userfiles/files/ponogejap.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/67236903459.pdfIn PDF document text
    • http://kuryakyn.ru/userfiles/file/zipuxemuwe.pdfIn PDF document text
    • http://hoaisonland.vn/upload/files/bitozejexovefikogew.pdfIn PDF document text
    • http://maroba-zirndorf.de/file/39630997557.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/if2egnbs3nipu1cq6773ljrqr4/91278891794.pdfIn PDF document text
    • http://w-w.cn/isee/pfm/cms/uploadfile/fck/file/zojulexagipodelidagavaja.pdfIn PDF document text
    • http://luyenthidhcanhsat.com/Images_upload/files/20871570640.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/88855766625.pdfIn PDF document text
    • http://anpo.vn/upload/files/64414787708.pdfIn PDF document text
    • http://conomiya.com/images/uploadedimages/file/36147926712.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161433dc4f30c1---xalisopozariwomo.pdfIn PDF document text
    • http://positiveforce.in/uploads/files/bexezotekosar.pdfIn PDF document text
    • http://goghepcacloai.com/media/ftp/file/kifozaxetibo.pdfIn PDF document text
    • http://dkkarsin.pl/img/upload/files/dujojadomimituwi.pdfIn PDF document text
    • https://alcoolassistance-creuse.net/www/site/js/ckfinder/userfiles/files/sisavesegufobunoji.pdfIn PDF document text
    • http://senvietsystem.com/ckeditor/upload/files/pasabaxi.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135b55e55f0d---14511359534.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b7c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cfd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFD6 19380 bytes
SHA-256: 0f159743945a8c44cfe8d34f760bf14884787cc58a89c45c86db81bcad57172d
font_02_sfnt_off00010124.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10124 10704 bytes
SHA-256: c2253923f3e0663c854ef3b35815b831f7b98e479717e687ad8b5ab97601b5a2
font_03_sfnt_off0001197e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1197E 1680 bytes
SHA-256: 6c08887b596ecb472c5a0482df8c2f828d83fc5b5d16111ed0caa1fced1b35dc