Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa5723f4d3e4ccea…

MALICIOUS

PDF

82.2 KB Created: 2021-09-07 06:54:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8e525d248b1bf2935d564749b90c8231 SHA-1: 57e245d5034e713ad6f274e602fd4b0268c37115 SHA-256: aa5723f4d3e4cceaf262656415391cc5a71089debd7aaf12654495fd44da102d
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a link farm, with numerous embedded URLs pointing to external resources. Several of these URLs are hosted on compromised CMS upload directories, suggesting an attempt to lure users to malicious content. The ML classifier strongly indicated maliciousness, supporting the interpretation of this PDF as a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 https://www.herewardcarpets.co.uk/wp-content/plugins/super-forms/uploads/php/files/9amiq1euv65o5i4lr4hl28fl3u/zafefolizibi.pdf In PDF document text
    • https://isagrinio.gr/userfiles/zuzamosipemibiva.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/jofof.pdfIn PDF document text
    • https://mabuksusu.com/contents//files/jojedomakot.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16125209359394---nuwulopoxidosetunuz.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/a026d60a078d8c076e085710e1bee1ea/92620849441.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/84755515106.pdfIn PDF document text
    • http://soepcentrale-dekeyser.be/userfiles/file/79138546163.pdfIn PDF document text
    • https://footballsod.com/images/ck-uploads/files/zetibi.pdfIn PDF document text
    • https://aljuboori.com/userfiles/files/30862230768.pdfIn PDF document text
    • http://auto4-spb.ru/public/images/ckfinder/files/wofaroniramunibudekuveri.pdfIn PDF document text
    • http://minhnguyenvn.com/uploads/userfiles/file/25184304589.pdfIn PDF document text
    • https://tidymoney.com/ckfinder/userfiles/files/pegolezupenusutaxu.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff6d10f09a---tirarajegeguxazekava.pdfIn PDF document text
    • http://bajcsidavidfoto.com/_user/file/32130528320.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072604cf37c0---vapebudugojupi.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/ec481be2mquf6oeel3998rcddb/58214514787.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ac31fd4c5c---kagovovogaliv.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160961ccd453fa---84870838304.pdfIn PDF document text
    • http://www.kizkulesikizogrenciyurdu.com/public/ckfinderuploads/files/mojaboxonorokaxeruxevusoz.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160898d844c9ea---kikipo.pdfIn PDF document text
    • http://airsoft1.ro/files/file/34281264254.pdfIn PDF document text
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/81ec74d489a4d313e6108a2a76bb7c36/83136219281.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=macrosomia+fetal+pdf+acogPDF 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_off0000d9e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9E5 10852 bytes
SHA-256: d4df4f5c412da088178859d49b8ebc7d7cbbab01adba95f4c03e3be91acecf09
font_01_sfnt_off0000f2c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2C6 18796 bytes
SHA-256: 60f2893686dcf6467c2917c406b9b7c1686f85d890d9157358c814792773dc54
font_02_sfnt_off0001237c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1237C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1