Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1b4b6370154b3e8…

MALICIOUS

PDF

95.2 KB Created: 2021-10-10 17:18:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 611557523d01fc1687df37cf847a714c SHA-1: 7a25461b68698db64a2c6e083e03255c07246758 SHA-256: d1b4b6370154b3e89774c91340a030eb8778661142952a15c636187f9849e24c
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 CMS uploads or disposable hosting. The ML classifier strongly indicates maliciousness, and the presence of a link farm suggests an attempt to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, providing no further context.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://krisoc.ru/uplcv?utm_term=dead+horse+state+park+dogs PDF link annotation
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/46475458518.pdfIn PDF document text
    • https://istanajpdua.com/contents/files/suvuvugenu.pdfIn PDF document text
    • https://ritascreation.com/userfiles/file/30502215249.pdfIn PDF document text
    • http://fiumevivo.it/userfiles/files/wijurev.pdfIn PDF document text
    • http://bscartridge.com/pic/zojaduxoraf.pdfIn PDF document text
    • https://emilline.dk/ckfinder/userfiles/files/roxajafegidu.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/72160009412.pdfIn PDF document text
    • https://sahyadrisevasanstha.in/userfiles/file/13780771146.pdfIn PDF document text
    • http://phutungotodungha.com/img/files/35090989569.pdfIn PDF document text
    • https://aramlasmerok.hu/uploads/file/zulisefebubibomupaxik.pdfIn PDF document text
    • https://beehaviour.nl/userfiles/file/jurovijikamisibexof.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16160bc2c8818b---tinuzasozizi.pdfIn PDF document text
    • https://www.barefoothoa.com/webroot/js/ckfinder/userfiles/files/84805886075.pdfIn PDF document text
    • https://jyapa.com/jhuoyue/uploadfiles/91248641883.pdfIn PDF document text
    • https://nabijdefossa.nl/upload/files/28315300269.pdfIn PDF document text
    • http://dgxzz.com/uploadfile/file/90407434925.pdfIn PDF document text
    • http://restauraceeverest.cz/userfiles/file/livetalu.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/rr0psafhs2ji218ha338f4foei/selazebitevejeweber.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/rtr80t1sroofn8tsbqm0tl0hsh/morusukazepebipiz.pdfIn PDF document text
    • http://gostinica-domodedovo.ru/files/zekelawukukob.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/3074c809b51b9dc2707a0f3c55867620/zikoxupivezomizotesamudix.pdfIn PDF document text
    • http://formacio.fic.cat/uploads/file/2842219714.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/72732563651.pdfIn PDF document text
    • http://sgrappresentanze.eu/userfiles/files/25326480677.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010c5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C5B 10524 bytes
SHA-256: dc963a33980484bb22b943e9aaef443e611ee45ce89d0254724f27045bb06c6c
font_01_sfnt_off00012443.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12443 19488 bytes
SHA-256: f18713d77dc5b64ab544b2aef3fbfd00f41a9ba405848fb8f2496ba98d3cc8a7
font_02_sfnt_off00015768.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15768 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1