Malicious PDF — malware analysis report

Static analysis result for SHA-256 bad2831a438b97c2…

MALICIOUS

PDF

83.4 KB Created: 2021-07-03 02:06:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5a8b3bb1efbd5526076b68e4abed96ad SHA-1: f177f42e3aaf3c0d19e4fa1054022c502440a250 SHA-256: bad2831a438b97c2e5c5f9ad401547483ac31b80fd78dbdaa7fb8992fd4e4d15
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload storage locations and disposable hosting sites, likely for phishing or malware distribution. The embedded URLs, such as 'https://synerhu.ru/uplcv?utm_term=disclosure+conflict+of+interest+statement', are designed to lure victims into clicking, potentially leading to further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • 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.
  • 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=disclosure+conflict+of+interest+statement
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16074c28a72d01---gapetajedutuwukesexutep.pdf
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f3e1f8c53f---16395174352.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/qbl4qq1scgvk02vauokngrpecm/54438256059.pdf
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7978c498e8---77077764727.pdf
    • https://alajuusa.ee/media/contents/file/wulamowolimelikulapij.pdf
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080d3493e8e0---79030912982.pdf
    • http://www.ecvbrass.ch/user/web/file/38175761423.pdf
    • http://juniorsmagazine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ed4f77cc63---pajabetepebujo.pdf
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160710a91bffa7---33558394470.pdf
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac854ce16cf---86486746491.pdf
    • http://hurtmar.pl/Upload/file/94013105036.pdf
    • http://yorkiematch.com/clients/6/65/653dc45b8f6063886304ac4260dbb99c/File/44463425347.pdf
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/531fa97188c1417b4abf8e48467994e7/xalodoxuruwulok.pdf
    • http://toanlinh.vn/upload/files/20798821151.pdf
    • https://advantagelic.com/singhania/downloads/file/46340980234.pdf
    • http://shuimotongyuan.com/userfiles/file/28120856389.pdf
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/e7aqpj7evadenfoq9kbr33sn22/ruxomevufozuve.pdf
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/a11242ef5b3e15f54cc8a03bd49fa178/23670306130.pdf
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/8e4d8f8d7ae86a98f4e5e8aac9444fbf/22757354544.pdf
    • 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_off0000e2e1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2E1 16792 bytes
font_01_sfnt_off0000faf3.bin
99a6b9eb28a86dce2bccecfc9418a45870da62009dbac180e6b16063d5bfac6c
pdf-font-stream PDF embedded font (sfnt) at offset 0xFAF3 16740 bytes
font_02_sfnt_off0001264f.bin
923d6b4b923e3c373589c6018af7cb5380f377a08977d336c49ace1da3db6e7a
pdf-font-stream PDF embedded font (sfnt) at offset 0x1264F 10600 bytes