Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1cd78858d1147c2…

MALICIOUS

PDF

72.1 KB Created: 2021-09-06 05:25:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d9c1f13f32840eb692e47b91c67bd926 SHA-1: 8e2cf9e61154a9d9477e7d57d8d17465ab1cc0d7 SHA-256: b1cd78858d1147c296764fed54dc8197e495dfd95fac3a88bdf9e6b23ed61ee1
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a large number of external URIs, many of which are hosted on compromised or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution through a link farm. The embedded JavaScript is a common technique for executing malicious code within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://majortaylorride.info/images/uploaded/file/70711091448.pdf In PDF document text
    • https://yuanfuconstruction.com/ckfinder/upload/files/peduwitujegodimumore.pdfIn PDF document text
    • http://bellina.pl/userfiles/file/80093825941.pdfIn PDF document text
    • http://ildongwire.com/userfiles/file/zororojapurezabid.pdfIn PDF document text
    • http://abhinavabhishad.org/userfiles/file/pigeruzusoda.pdfIn PDF document text
    • http://www.phuongdonggolf.vn/app/webroot/uploads/files/finol.pdfIn PDF document text
    • http://rosritual.su/app/webroot/js/ckfinder/userfiles/files/suvifax.pdfIn PDF document text
    • https://callmarkinvestments.fortunekenya.com/callmark/files/pukalerilovuv.pdfIn PDF document text
    • http://johnmichaelharrisonlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dumojonusik.pdfIn PDF document text
    • http://murphysbeads.com/clients/54316/File/18433175804.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/zitexejovoriwuwu.pdfIn PDF document text
    • https://daqing-jewelry.com/uploads//files/202108031006455446.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609002bf735a7---40862806713.pdfIn PDF document text
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/2hphqn2ii6ajn3s72s2jnroqkh/jawurodapukobedorika.pdfIn PDF document text
    • https://shoreluxurylimos.com/userfiles/files/pupijinepedamugum.pdfIn PDF document text
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/e89ksv79nolnna55c4ig9neku0/falapume.pdfIn PDF document text
    • https://www.peltonfell.org.uk/ckfinder/userfiles/files/depokijaxugasoved.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609297b41f6a0---14069040365.pdfIn PDF document text
    • https://arerp.kr/data/file///xegixiruvepelotuliz.pdfIn PDF document text
    • http://word.mn/uploads/assets/47455824642.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/kfrbc7jgbg7pi58f9l9p444kf7/momofipepobazuregatupaj.pdfIn PDF document text
    • https://realxenon.ru/uploads/files/66521740286.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b25b1d1ca4---66702973875.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/40985504298.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=coffing+hoist+manualsPDF 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_off0000b6f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6F5 10560 bytes
SHA-256: d65a36b263de26c13608e71b1bf1d4fd31454b95db6ea1aac6671c30c73699cc
font_01_sfnt_off0000ced9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCED9 16432 bytes
SHA-256: 10bc048f40e3d1c0224f655e32d175fcde5049e97c2197bd57bb1504a1778162
font_02_sfnt_off0000f8f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1