Malicious PDF — malware analysis report

Static analysis result for SHA-256 959bd1597ef7fd76…

MALICIOUS

PDF

76.7 KB Created: 2021-09-18 20:06:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 84ced6b5739c4e9a3a0897fdae71dccb SHA-1: bb38bd6fe355250af08fb662dd3ce351b7fd28d1 SHA-256: 959bd1597ef7fd76f3edff3fe60b365bc6a492ac5a973d9f2d2ebfa547062fa3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous embedded URLs pointing to potentially compromised websites. The presence of external URIs and link farms suggests the document is designed to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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=grey%27s+anatomy+season+2+123movies PDF link annotation
    • http://ferrocom-spb.ru/userfiles/files/91317007452.pdfIn PDF document text
    • https://escolaalfa.com/userfiles/file/71566161842.pdfIn PDF document text
    • http://www.jysunshine-hotel.com/up_files/file/94350985830.pdfIn PDF document text
    • http://kleinschaden-expert.com/userfiles/file/puxezozimugil.pdfIn PDF document text
    • http://ehomerealestate.org/images/file/joripozuj.pdfIn PDF document text
    • https://cemb.ca/upload/editor/file/76253085182.pdfIn PDF document text
    • https://advance-pack.com/editor_upload/file/dopekuxe.pdfIn PDF document text
    • http://businesslegalgroup.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rixuzikal.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/b9a34afa62ec69e96d951ba1e604883d/63873991597.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/sijulebinu.pdfIn PDF document text
    • http://wmasgroup.com/userfiles/file/86287456362.pdfIn PDF document text
    • https://badanie-wody.pl/galeria/file/dudidoporu.pdfIn PDF document text
    • http://fratellibeninca.com/images/file/29169854043.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/paputewinukubuguziw.pdfIn PDF document text
    • http://pkpneu.cz/userfiles/file/joboxizapujid.pdfIn PDF document text
    • http://www.dkmodels.net/ckfinder/userfiles/files/sudupajumigonav.pdfIn PDF document text
    • http://lifeline-sports.com/files/file/mafamaguxigaze.pdfIn PDF document text
    • http://nhasachnguyenvancu.com/Images_upload/files/73631948426.pdfIn PDF document text
    • http://mackielaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nowepudok.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/0a4d53175f28e4fa1dc808fb76855fce/97397905214.pdfIn PDF document text
    • http://cctechlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/3519456090.pdfIn PDF document text
    • https://dakotaterritorydevelopment.com/ckfinder/userfiles/files/nitelusalizedeluruka.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613382dc0dc1d---7458032045.pdfIn PDF document text
    • http://rulife.ru/ckfinder/userfiles/files/fiterowifew.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_off0000c943.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC943 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e155.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE155 16316 bytes
SHA-256: 1f66a3cda38c56b6dcbe0aaeb4abab9eb638af41bdadea47879e6126c2b231ba
font_02_sfnt_off00010bbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BBD 10820 bytes
SHA-256: a5ad2ccfff5f20db6d4b7ab2a2a377d98bc39a9c05a7280bea070ac8eec94d7e