Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3e13ce1ea0dad8c…

MALICIOUS

PDF

80.0 KB Created: 2021-10-14 21:52:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 45c130a365f1b9d4d7320348ab372112 SHA-1: 9ba226b7c5bd2dfda5112c9f0cc04fd36e8cd3fc SHA-256: b3e13ce1ea0dad8c170949f469f2fce4784a5facb2ce51b6da141d0b5202d24b
96 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised WordPress sites. The ML classifier strongly indicates maliciousness. The file's structure and numerous external links suggest it's designed to redirect users to potentially harmful websites, possibly for SEO spam or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16163b155a2fd2---luzuzikaxamimimitewi.pdf In PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/vuxumodon.pdfIn PDF document text
    • http://damutech.kz/upload/2021/09files/2109270902524779208ki0t.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/16164cf4b572fc---53154101227.pdfIn PDF document text
    • http://ctyrkolky-gamax.cz/data/dokumenty/poduju.pdfIn PDF document text
    • http://chinastom.ru/userfiles/file/15445274500.pdfIn PDF document text
    • http://wecans.net/_UploadFile/Images/file/sixusubufi.pdfIn PDF document text
    • http://deborahkay.com/ckfinder/userfiles/files/nezezewelafafedonelori.pdfIn PDF document text
    • http://wyadonline.com/userfiles/file/linalafusogadojerixev.pdfIn PDF document text
    • https://yingzhaoliuart.com/upload/file/josawukazikisovuve.pdfIn PDF document text
    • https://halkum.rs/files/66257785439.pdfIn PDF document text
    • http://metrominicabs.com/survey/userfiles/files/nemopovozabapipigizolawot.pdfIn PDF document text
    • http://jessie.vn/images/ckeditor/files/xuremuvofuja.pdfIn PDF document text
    • http://businessplan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/jimubozizejoke.pdfIn PDF document text
    • https://deltagroup.bg/uploads/file/14217045605.pdfIn PDF document text
    • http://jjburgerut.com/uploads/files/63837942519.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131a80ee54b7---25317853731.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133b2aa6abbf---10284970727.pdfIn PDF document text
    • http://www.hussco-steel.com/husscofiles/files/xipibujuzabowo.pdfIn PDF document text
    • http://vo23.ru/upload/file/69548347164.pdfIn PDF document text
    • http://cuacuongiare.vn/upload/files/nimekuzofori.pdfIn PDF document text
    • http://www.kigimex.com.vn/ckfinder/userfiles/files/pilorelaximevusufanadat.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/896FEnmJZlk/uplcv?utm_term=mother+teresa+factsPDF 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_off0000d5eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5EB 18064 bytes
SHA-256: 3cb5c078f2fc14abf3607dc73168e68af3f28cd14938b3e3a8f47769c6bdb03f
font_01_sfnt_off000103e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011bf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BF9 10184 bytes
SHA-256: c435e6b8f9d10707d2cf16619547146ab0a696b2f4ff1ae52a85c2ed4d40579a