Malicious PDF — malware analysis report

Static analysis result for SHA-256 fa98c7f4e87eae3d…

MALICIOUS

PDF

72.6 KB Created: 2021-09-25 17:06:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 1ff3d74b746af85377af249dab0d762e SHA-1: 7acdb4f0a35a065e431617297add7bea24823b96 SHA-256: fa98c7f4e87eae3dbee1b39711d43f1b4a1cd7803f20279f92473fd3b5bd97f3
104 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 acting as a link farm. These links likely serve to obscure the final malicious destination, which is probably another malicious document or exploit. The ML classifier strongly indicated maliciousness, supporting the presence of malicious JavaScript and a link farm designed to evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/fntnk4mfdj83g0dla2fnp8qla2/tidabajirofukoxobinizo.pdf In PDF document text
    • https://indirimlipin.com/calisma2/files/uploads/37813758271.pdfIn PDF document text
    • http://imhome-listings.com/userfiles/files/fevafomomabujuxuzujur.pdfIn PDF document text
    • https://yasacompany.com/upload/files/pogotenigadikanevibewux.pdfIn PDF document text
    • http://perles-del-beya.com/userfiles/file/ramobigunizopilasak.pdfIn PDF document text
    • http://flooroverstock.com/admin/userfiles/file/zonomuwuwixuzuw.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395b99646ab---5198471396.pdfIn PDF document text
    • https://andana.us/files/files/fibosefowogajuromapiveto.pdfIn PDF document text
    • http://propertiesforrent.com/userfiles/file///ravopeluwonixa.pdfIn PDF document text
    • http://motocams.cz/ckfinder/userfiles/files/kisexuwinozomuxikizu.pdfIn PDF document text
    • https://sesconbs.org.br/ckfinder/userfiles/files/kepebuju.pdfIn PDF document text
    • http://nathulaldasptti.com/ckeditor/ckfinder/userfiles/files/wopugef.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/86311605335.pdfIn PDF document text
    • http://uktohabbarijamalta.com/files/file/920846556.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8699caeab---renosuwusivevilaxudikira.pdfIn PDF document text
    • https://trungtammatnamviet.vn/upload/files/55210358046.pdfIn PDF document text
    • http://denetimmusavirlik.com/userfiles/file/vobatomulux.pdfIn PDF document text
    • http://carnow.jp/js/upload/files/gusux.pdfIn PDF document text
    • http://dennehylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wexipumelaxulajufiwu.pdfIn PDF document text
    • http://xecuoihuyhoang.com/uploads/userfiles/file/gotofunime.pdfIn PDF document text
    • https://togeltop.net/contents/files/tuxobofikovubexilem.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/81723a130e90cfd01242be30ad97e1ec/91268809598.pdfIn PDF document text
    • https://xn--lenachatka-57b.pl/uploaded/file/65590118306.pdfIn PDF document text
    • http://tieuhocsongphuong.hoaiduc.edu.vn/ckfinder/userfiles/files/jovowewalikaguxixa.pdfIn PDF document text
    • http://xn--80aadcnaeutgftohcogh8i8dsc.xn--p1ai/pict/file/mukomezawotobuxokaw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=redmi+5+new+update+2020PDF 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_off0000b767.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB767 10728 bytes
SHA-256: c1cd67e9dacb776f834df5b474482cd0b194bf48c92b06b4684619fbb6b8efb5
font_01_sfnt_off0000d027.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD027 17432 bytes
SHA-256: 2ac1331c108f06a4b5caba03894d2f3e476c4e284843c49a5e5be5fb7876c1b9
font_02_sfnt_off0000fca7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCA7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1