Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c20b35375d085a7…

MALICIOUS

PDF

78.9 KB Created: 2021-10-18 07:27:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 9089cc275535dc8956e7dc248307bb35 SHA-1: 6e097d8003d92aa6fde66f52b2a02b4977078f4e SHA-256: 3c20b35375d085a7f69ea42ed7da87683969cf75d5adf87063e5f7cc3bff24c9
126 Risk Score

Malware Insights

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

The PDF was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The presence of numerous external URIs, many pointing to disposable domains and configured as a link farm, suggests a phishing or malware distribution scheme. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates the document's purpose is to redirect users to a network of potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://alimentosldm.com/userfiles/file/27326777395.pdf In PDF document text
    • http://www.elstar.ru/uploads/files/nenojovoruzisipevirusefi.pdfIn PDF document text
    • http://ekouklid.eu/UserFiles/file/liwodew.pdfIn PDF document text
    • http://wtmongolia.com/materials/file/mafukasenodawugireri.pdfIn PDF document text
    • https://faktxeber.ru/resimler/files/risibitedukerubar.pdfIn PDF document text
    • http://kdsonline.org/userfiles/file/15335035485.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/161662f2c782b9---negiz.pdfIn PDF document text
    • https://archielectronics.com/userfiles/files/pamiwiji.pdfIn PDF document text
    • http://salt17.com/userfiles/files/50271091019.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/kokiwulaxowip.pdfIn PDF document text
    • https://burgaseguros.com/userfiles/file/ziburebopigozujal.pdfIn PDF document text
    • http://yejida.com/userfiles/file/gimanatalarep.pdfIn PDF document text
    • http://robfredo.com/userfiles/file/61128816242.pdfIn PDF document text
    • http://vekosgroup.ru/userfiles/file/34313646578.pdfIn PDF document text
    • https://www.hosotte.com/ckfinder/userfiles/files/lozemezojewubufirugiwedi.pdfIn PDF document text
    • https://santa.sg/images/users/00000000/files/70403794196.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/tigaliranijoxiduzudotati.pdfIn PDF document text
    • http://agt.es/files/galeria2/files/63646409159.pdfIn PDF document text
    • http://wuxihemei.com/ckfinder/userfiles/files/20211003_024244.pdfIn PDF document text
    • https://sibirprokat.ru/ckfinder/userfiles/files/14736012378.pdfIn PDF document text
    • http://border-collie.ru/sites/default/files/file/61214925869.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/u93b1khafmkdvc7m6nc1u6ta8c/vudipoduguvuxab.pdfIn PDF document text
    • https://bolahijau.com/contents/files/32675502708.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/896FEnmJZlk/uplcv?utm_term=what+happens+to+particles+when+a+solid+meltsPDF 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_off0000d34c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD34C 16188 bytes
SHA-256: b80542d338773ba98a6c30d47d67ad7306ff3f04ccd0f4ac30134fdb33d2b450
font_01_sfnt_off0000fd2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD2E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011545.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11545 10860 bytes
SHA-256: 00d7f0afa3e7218735cf0945e6931fd2d3540436484012e00ff07425b8e5dbc8