Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3535dc67b16d7bd…

MALICIOUS

PDF

74.3 KB Created: 2021-09-17 03:59:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 44bd7f515e4072692eb36b90b63d201f SHA-1: 2a372de99d0a52042c9ba2aee80ec3717e73f783 SHA-256: d3535dc67b16d7bdd5f3b8044313eec5f2307ae133c98c10d5424f51140b57ac
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting domains, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple link farm heuristics supports the conclusion that this document is designed to direct users to potentially harmful external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://dragonexpressml.com/userfiles/files/tisivaxowozije.pdf
    • https://mysilo.com/upload/ckfinder/files/4209098228.pdf
    • http://projecthouse.bg/uploads/CKfinder/files/47834686749.pdf
    • http://kaizenlife.com/ckfinder/userfiles/files/tewakivuvojujemigig.pdf
    • http://ipceurope.be/assets/file/65259509119.pdf
    • https://taipeitccia.org/CKEdit/upload/files/38284094649.pdf
    • https://aparcaderoshaddaichile.cl/uploads/images/files/wumowap.pdf
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613671143b313---rirobi.pdf
    • http://veronikavilla.hu/userfiles/file/dotikizakosopewus.pdf
    • http://makaroma.fr/upload/file/ponux.pdf
    • http://kfnmdg.com/upfolder/e/files/20210914190133.pdf
    • http://sictombbi.fr/ckfinder/userfiles/files/wesubopedumirapifovubuj.pdf
    • http://vtdsbinhthuan.vn/public/uploads/userfiles/file/waxezuraluraridi.pdf
    • http://gwtcs.org/Content/uploads/files/vejubepobuvudobipa.pdf
    • https://satesayap.com/contents/files/femuz.pdf
    • http://churchtextile.com/userfiles/file/viwaxuni.pdf
    • http://www.fred-robin.com/ckfinder/userfiles/files/gupazavul.pdf
    • https://www.wappa.com.au/siteadmin/ckfinder/userfiles/files/kogeromafufitaje.pdf
    • https://angkoronetour.com/userfiles/file/28069375673.pdf
    • http://synergienetwork.net/userfiles/file/68728227225.pdf
    • http://ags-sib.ru/ckfinder/userfiles/files/6194990615.pdf
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/82902882492.pdf
    • https://onderdurdu.com/upload/ckfinder/files/fapebamavepexopuj.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161356a9ed0c67---34377326346.pdf
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/0sen19im0tn1n0ee9pq9227bi3/delekunupomuwonarum.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=active+root+apk
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c0b6.bin
1ad107e33299b8ceb121ef3d305593c700b7009d1d8da30b0365b80224a2176c
pdf-font-stream PDF embedded font (sfnt) at offset 0xC0B6 17068 bytes
font_01_sfnt_off0000ed0a.bin
1262b761e50fa40ceaa3989271ce1298ef49379f21060f02b29a886b707e4d03
pdf-font-stream PDF embedded font (sfnt) at offset 0xED0A 10188 bytes
font_02_sfnt_off00010414.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10414 16792 bytes