Malicious PDF — malware analysis report

Static analysis result for SHA-256 838566f9149fbd43…

MALICIOUS

PDF

84.6 KB Created: 2021-09-02 07:59:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 1640374f9b38b9a04c848d06e2b8c0da SHA-1: 474a0d1de0cf967ebd37f3b3b467bab1d2c6f282 SHA-256: 838566f9149fbd43811c293335172b4ce9623ee9ee00a6b47cf4a441381b16f1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to other PDF files hosted on compromised websites. This pattern is commonly used for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9918

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://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b80629b903d---44005996319.pdf In PDF document text
    • http://villabrown.it/userfiles/files/90668285555.pdfIn PDF document text
    • http://minniemleefamilyreunion.com/clients/4/46/4626b253669c69ed517e077132fb6553/File/60496764142.pdfIn PDF document text
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/3i2dn2b5klpoi6v6jtcu1c7t8a/mirugi.pdfIn PDF document text
    • http://csc-0898.com/userfiles/file/20210719071752_6dvtjl.pdfIn PDF document text
    • http://veterinariogiardinelli.it/userfiles/files/wavilufora.pdfIn PDF document text
    • http://kingnature.ru/files/files/23201739864.pdfIn PDF document text
    • http://caydinhlang.net/userfiles/image/file/66521329647.pdfIn PDF document text
    • http://rudolphalexander.com/uploads/files/zigawalavuxo.pdfIn PDF document text
    • https://ahreco.com/uploads/news_file/41865461720.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/554c0c2c97b955abc0005f9def1477c8/79205412500.pdfIn PDF document text
    • http://trunglam.vn/uploads/userfiles/file/megetapekesixif.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/768047da7912a1bc893fd958d289adfd/11005724985.pdfIn PDF document text
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/91560949868.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/422abb9cae35670b7b2e08e986ce4168/kabikak.pdfIn PDF document text
    • https://beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/e823a6558e9e813b04eac205cd4ecd07/wokitem.pdfIn PDF document text
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/bf85a9c7b1187f937b5efb64e49113d3/53507905141.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/706h43ihjc929lo8l70mi8or5u/povivu.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/98561505614.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610f1d52ac50c---pidof.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/su5qulcajog48cjop2mfom6q41/suxara.pdfIn PDF document text
    • http://whuntex.ru/userfiles/file/3493404247.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/e830646c156b716bd536fa219d15b132/42469000739.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/k0d639mvah2lie2g1nkp4h71sa/4661245416.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16096f4f71afa0---raxupazixamezojojonisoti.pdfIn PDF document text
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d0128345f---megixoxuzafil.pdfIn PDF document text
    • https://faprosid.com/file/89118534755.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=oxford+referencing+style+pdfPDF 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_off0000e403.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE403 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC1A 10876 bytes
SHA-256: a3e7139cde1cd7e744e8846e9a53eeff2d4e945b461353943412b3274c5907c2
font_02_sfnt_off0001152c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1152C 18212 bytes
SHA-256: 67876e86a3660bba0615d40c6822b472b79c3f447634f553dcf4b2aa69527b49