Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a169cc349f36d24…

MALICIOUS

PDF

92.2 KB Created: 2021-09-15 18:08:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 072c97e3d5dfa4b7060a0004da005a29 SHA-1: 6f22f8e94fcec0c974be7b51e60546e1ef58acf0 SHA-256: 4a169cc349f36d2415d23c0d0359c9747d7cfa59738505fabc0af878a55aa688
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 https://synerhu.ru/uplcv?utm_term=2021+mmorpg+games+pc PDF link annotation
    • https://akamercedes.com/images/uploads/files/nujemerutokawena.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e5463a780---buzikegegebasubo.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16131b98ba4cad---retebili.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/jazanusulakobina.pdfIn PDF document text
    • http://www.forteks.com.br/admin/ckeditor/ckfinder/userfiles/Images/73415516382.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/895ccc8aeae35e647bb3b1efd6cb8f76/nujuporumip.pdfIn PDF document text
    • http://villa-margherita.biz/userfiles/files/xawekixezemilitelugowefib.pdfIn PDF document text
    • http://inruho.ru/ckfinder/userfiles/files/81413494283.pdfIn PDF document text
    • https://sport-jicin.cz/dokumenty/fobupifa.pdfIn PDF document text
    • http://bsp-plovdiv.org/ckfinder/userfiles/files/40823829484.pdfIn PDF document text
    • http://fredericjean.net/oplusco/file/18335763912.pdfIn PDF document text
    • https://cartolmania.it/file/lezeg.pdfIn PDF document text
    • https://sistemagestiondpr.com/userfiles/file/96819861901.pdfIn PDF document text
    • https://tidurmalam2.com/contents/files/78195703188.pdfIn PDF document text
    • http://oldadmin.k12cart.com/media/files/47280726146.pdfIn PDF document text
    • https://pmfegypt.com/userfiles/files/64162105600.pdfIn PDF document text
    • http://tipkeo.com/js/ckfinder/userfiles/files/1177111832.pdfIn PDF document text
    • https://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/b68309fb19cf938bd20d0b03e703146d/11153810777.pdfIn PDF document text
    • http://aalzkj.love-mrt.com/upload/files/9799157191.pdfIn PDF document text
    • http://dragonera.cn/admin/userfiles/file/7131537538.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614148d27a736---1934083349.pdfIn PDF document text
    • https://mahanakhon.pacedev.com/ckupload/files/popumimuwavevijiker.pdfIn PDF document text
    • http://aristosaigonhotel.vn/uploads/files/mixewaguzid.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_off0001044e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1044E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011c60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C60 17940 bytes
SHA-256: a2dc41c3b0523f0a698a5d30af4604de73a2455c0a856afe61d0db787561eaea
font_02_sfnt_off00014af8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14AF8 10576 bytes
SHA-256: 8ea6861bce11c2547bdcabb22d79105e28545c81c56fc677739ff579b4072364