Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a8b66c6ad5cfdee…

MALICIOUS

PDF

80.0 KB Created: 2021-09-18 11:44:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: cf68de33028749146028cc3536ce6e94 SHA-1: 54eb6b529619a15f8ea5ff2de378704245fb5aba SHA-256: 0a8b66c6ad5cfdee46c400354d0ca838d8a6cc2893f9c6135971b74e0705510a
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document exhibits characteristics of a link farm, with numerous embedded URLs pointing to various domains, some of which are hosted on compromised CMS platforms. The ML classifier strongly indicates maliciousness, and the structure suggests an attempt to manipulate search engine results or redirect users to potentially harmful content. No scripts were extracted, but the presence of multiple external links is a strong indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • 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 http://rockpapersun.com/upload_mce_image/file/25523927945.pdf In PDF document text
    • http://www.neoneophytou.com/ckfinder/userfiles/files/57404996108.pdfIn PDF document text
    • http://kronikarp.pl/ckfinder/userfiles/files/31480742102.pdfIn PDF document text
    • http://autoscuolepintozzi.it/userfiles/files/sajevuvewasulukuse.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/d85f1343b9afe31d186d64d6def20e62/tivevatafere.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16140e7dd42e59---vixiseti.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/e26660c69a48f2eb642f6184351e05ab/54043099408.pdfIn PDF document text
    • https://eniedu.com/data/file/20210902050047.pdfIn PDF document text
    • http://eia-edu.com/userfiles/file/57170992146.pdfIn PDF document text
    • http://keemunblacktea.cn/uploads/file/040110262165.pdfIn PDF document text
    • https://www.shipgo17.com/plugin/ckeditor/ckfinder/userfiles/files/nugoka.pdfIn PDF document text
    • http://okun.su/upload/file/pusijirugufulaw.pdfIn PDF document text
    • https://bursac.net/userfiles/file/sijalozebemiku.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132e46a28f89---sibal.pdfIn PDF document text
    • https://armour-technoz-ca.otzol.net/ckfinder/userfiles/files/87138134022.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210913205908042.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/161412bed603c9---73595250187.pdfIn PDF document text
    • http://thienanglass.vn/upload/files/zizefolunosisajik.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/febuzovefejitepono.pdfIn PDF document text
    • https://xn--espaoldetalca-lkb.cl/var/www/html/upload/file/96884785782.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/161422820135c3---junukutoturiforor.pdfIn PDF document text
    • https://fentesmakina.com/paket/upload/files/pebolurapusiporez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=gt+s5360+hard+resetPDF link annotation
    • 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_off0000d564.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD564 10620 bytes
SHA-256: e20151c0b43dc6cc2e7cd59427784f9f4119ecf164363e469f621de874b1e596
font_01_sfnt_off0000ede6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE6 17384 bytes
SHA-256: 5fc12ef17683087e26816e53b6ea5885ada78f15077306eb86e74c60db6a241c
font_02_sfnt_off00011a83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A83 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1