Malicious PDF — malware analysis report

Static analysis result for SHA-256 b0228870a6bfddb3…

MALICIOUS

PDF

83.2 KB Created: 2021-09-08 22:32:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6c5b2c38e2cadfc7c096cf10c883b2e0 SHA-1: 5d700509792f2baec2f4cbfcac36132873085c07 SHA-256: b0228870a6bfddb37e1fa2fea1e3ed223a383ede2bb5d4b5ba0c252059d7d9af
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, and multiple heuristics identified the PDF as a link farm. The URLs point to various domains, some of which appear to be compromised CMS uploads or hosted on disposable infrastructure. The document body is heavily obfuscated and unreadable, suggesting it's not intended for human consumption but rather to facilitate the redirection to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://irlanc.ru/uplcv?utm_term=things+to+put+in+a+minecraft+mansion PDF link annotation
    • https://gruntbudowa.pl/files/file/32235165119.pdfIn PDF document text
    • http://babyindex.nl/images/uploads/xavawabuvenozexaveme.pdfIn PDF document text
    • https://novinfasteners.com/userfiles/file/52899527598.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/161380ad850b51.pdfIn PDF document text
    • http://lynxitservices.com/ckfinder/userfiles/files/pevarosilom.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/26789730203.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/161309499179ec---nelekibakifapilobowop.pdfIn PDF document text
    • https://jiu-hang.com/upfiles/editor/files/vipepowemiral.pdfIn PDF document text
    • http://peterpan1996.it/userfiles/files/11347036287.pdfIn PDF document text
    • https://marathonlaval.com/userfiles/files/27199163336.pdfIn PDF document text
    • https://webmedcentralplus.com/userfiles/file/47318537240.pdfIn PDF document text
    • https://hinodecoder.com/userfiles/file/nugutixelokunukafami.pdfIn PDF document text
    • https://ap-qatar.com/userfiles/files/15904631286.pdfIn PDF document text
    • http://becucci.it/userfiles/files/80122209122.pdfIn PDF document text
    • https://egyediajandekotletek.hu/mvc/userfiles/file/zugazupi.pdfIn PDF document text
    • http://ajej.pretty-match.com/upload/files/gefixarokufamul.pdfIn PDF document text
    • http://travelsi.ru/ckfinder/userfiles/files/woxulajovoferaped.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613620bc421c2---mipogetawefufilibizebuvon.pdfIn PDF document text
    • http://faradbox.pl/files/file/69712999280.pdfIn PDF document text
    • https://vanvoorst.info/uploaded/file/tekowevafekujebekuf.pdfIn PDF document text
    • http://dfwsedan.com/nbloom/fckuploads/file/8729127566.pdfIn PDF document text
    • http://brno-skoleni.cz/ckfinder/userfiles/files/2239497874.pdfIn PDF document text
    • https://duel.pl/userfiles/file/zowodunaluvonu.pdfIn PDF document text
    • http://xinyaoqiye.com/upload_fck/file/2021-9-7/20210907190828458330.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_off0000e0d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D2 10944 bytes
SHA-256: 307e21dff4533f305e8a7c78f793a0a196d4f49305c11c4b184a1c06f79ec3e6
font_01_sfnt_off0000fa07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA07 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011219.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11219 17520 bytes
SHA-256: d995ce2a7b4dca966a3d36a51ed2c653a69566eb608bdefb6971443d19994b92