Malicious PDF — malware analysis report

Static analysis result for SHA-256 bff425cd96e99f0c…

MALICIOUS

PDF

81.8 KB Created: 2021-09-06 01:03:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e9d263c32e8b8e5a79c1703344f445b2 SHA-1: ee5fb94ea5de0af2f0f50b82e4a699e9453bf111 SHA-256: bff425cd96e99f0ca65617029cbe039e1baf6cadb7deca537502e6f69a0abab5
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded URLs and the nature of the heuristic firings point towards a tactic of directing users to malicious content, likely to harvest credentials or deliver further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://nomylo.ru/uplcv?utm_term=language+books+pdf+download PDF link annotation
    • http://ixtvs.de/_upload_bilder/_filemanager/file/37738508729.pdfIn PDF document text
    • https://bursakaynak.net/userfiles/file/dejuletuw.pdfIn PDF document text
    • http://lukoilmarine.com/ckfinder/userfiles/files/kijelulafozabidogudo.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611f1c50c0e90---bepatedapifelazilodim.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ca766b816c5---fifosegu.pdfIn PDF document text
    • http://cameradungphat.com/uploads/files/timopemixexaxasuw.pdfIn PDF document text
    • https://jagamimpi.com/contents//files/wadibuzusepevuxeg.pdfIn PDF document text
    • http://miryangpension.com/FileData/ckfinder/files/20210828_02C619E0EBF4F3A1.pdfIn PDF document text
    • http://thienlongadv.com/upload/files/viritilob.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/c14c74e7302d47307eff2314b932ffd5/71869312555.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080278122b83---zifunukedu.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/160fb18bae430c---kutegu.pdfIn PDF document text
    • https://topclassgreenery.nl/images/file/sopabebeximazajiwakejemez.pdfIn PDF document text
    • http://lovelyspa.net/ckfinder/userfiles/files/kidenopadejolosigip.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093a8eea1f6c---93701879862.pdfIn PDF document text
    • http://nomorecpapmachine.com/userfiles/files/27573014170.pdfIn PDF document text
    • http://ed-web.cz/userfilesfile/21879519583.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/a268sqkfeidp84ip6nmjnc8bvg/58942540972.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a47c54c3d74---44610171846.pdfIn PDF document text
    • http://rentbucharest.net/images/userfiles/xuvovozezan.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/9acdfecqikf2b2h1kogp069uf5/megasovonakakiweka.pdfIn PDF document text
    • http://xn--9i1b14l32gg2dsybq3b.com/upload/fckeditor/file/24467510826.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/16083030a28135---42103248327.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609ed77919369---27367868378.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_off0000dd04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD04 16940 bytes
SHA-256: b94ef1a68592c0e423719171413d816d463eb40ed536a4daf794322f17e5e970
font_01_sfnt_off000108e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000120f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F8 10756 bytes
SHA-256: fddbb283f7168accbbbf9dc35aad073d733214cceff2affb1afa89c2334b1666

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