Malicious PDF — malware analysis report

Static analysis result for SHA-256 883c13a847f52ae3…

MALICIOUS

PDF

78.8 KB Created: 2021-10-11 23:36:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c1eda6f1e8c5837843292fc93d656d43 SHA-1: 6500e7eaa1ae317dba7fda1738287bfba8a9fa5d SHA-256: 883c13a847f52ae33825b26e84f46ff45574688c04a17fb0808b647af2fa0ea0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware-hosting sites. The embedded JavaScript is a common technique for initiating malicious actions within PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://studiodara.eu/userfiles/files/45015519830.pdf In PDF document text
    • http://dkkarsin.pl/img/upload/files/sakotediziguburiz.pdfIn PDF document text
    • http://vip-cond.ru/userfiles/file/wezadaza.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/89980612476.pdfIn PDF document text
    • http://ctcinsulator.com/uploads/file/mifibironapituj.pdfIn PDF document text
    • https://sweetburden.com/upload/users/files/zegakatixate.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/bd1f549c15aec2b3f1851b60dc7a518b/xetozuxadukuguwekiwiri.pdfIn PDF document text
    • http://highendschmiede.de/highendfiles/file/9926359375.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/e2bdf8f9c9f47c04063f9f90a91351f9/sowuw.pdfIn PDF document text
    • http://inannamsao.com/uploads/files/tezagawenirubit.pdfIn PDF document text
    • http://autosvanbeek.nl/mindcms/js/ckf/userfiles/files/56041812646.pdfIn PDF document text
    • http://motorlustor.net/userfiles/file/80838754159.pdfIn PDF document text
    • http://zaiger.ru/img/file/67173677644.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/bt69657itcs2n07mcil4bspn79/lopegopijigelutoge.pdfIn PDF document text
    • http://balashixa.inhome360.ru/admin/ckfinder/userfiles/files/firesazowizinelusesupoli.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/bb57d0e2d0336710183f1fc7d7b87fd1/77289001055.pdfIn PDF document text
    • http://sbcnepal.com/images/file/datadasesupudujitaf.pdfIn PDF document text
    • http://kirsanov-maslo.ru/uploads/bojesobowifosakogudixixib.pdfIn PDF document text
    • http://ambulanceservice.pl/userfiles/file/negeruxuj.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/5bhJmFgkeCE/uplcv?utm_term=what+mbn+mean+in+textPDF 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_off0000ceed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEED 10176 bytes
SHA-256: d9fd5deb2e502185b1e47a0cf818b7d4f2e7727e3ad528be2f8f618232d76642
font_01_sfnt_off0000e586.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE586 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fd98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD98 18920 bytes
SHA-256: 0e7c69759f1cb4ff5697bbaa9f3241c46de88b7852df5796641a09f5cd0a7752