Malicious PDF — malware analysis report

Static analysis result for SHA-256 25cb38a55875836a…

MALICIOUS

PDF

86.7 KB Created: 2021-06-28 01:18:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3687565af5b726fa099a8782ea4b6006 SHA-1: 6f7e348cca80bcd7b363a363a06edf5f1804e3af SHA-256: 25cb38a55875836a81d123f5977b36bf3d49d1f7e369ff13863955e52cd8e847
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress upload directories, suggesting a link farm or phishing lure. ClamAV detected this file as Pdf.Phishing.Trojan, and ML classifiers also flagged it as malicious. The presence of embedded URIs and the nature of the heuristics strongly indicate a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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://liniagdanskzydowo.pl/files/65245850743.pdf
    • http://terminsk.by/pics/files/63992782924.pdf
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086daacb8ba2---bivokakepinegasokum.pdf
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16084671e8527d---51186637739.pdf
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/8ke8oufgm6pt9agcv7ape3628h/gopenekiboxobojafatavo.pdf
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607b0993336db---jizuza.pdf
    • http://gpszone.hu/upload/userfiles/file/kedud.pdf
    • http://eko-inwest.eu/upload/file/juxodas.pdf
    • https://gamasteel.net/userfiles/file/bobitakawakafefuz.pdf
    • http://greenbrier101.com/userimages/72863578079.pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/4eb8e670b2a3693b953179c60a7cb34a/56491478447.pdf
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/ereb942vdsuj991vol1g0td3t4/67485040564.pdf
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f5a356dfa---serexoninodasoni.pdf
    • http://novussiteyonetimi.com/uploads/file/fabuv.pdf
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4a5ece493a---86374707677.pdf
    • http://midiabyz.com/wp-content/plugins/super-forms/uploads/php/files/c05b11492d9bafcc7d136803e62929a6/tolinujagajisulerukena.pdf
    • http://alexhoffordphotography.com/temp/files/file/55113110561.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b8d01a4b8fa---fagetab.pdf
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16094905ec1a17---15415867814.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8ab7b883ec---wivesas.pdf
    • http://perilatomsk.ru/ckfinder/userfiles/files/69376996293.pdf
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c61c9d04ded---49163660475.pdf
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/fa9a1fe05c8bc064582ed1e054ba8a72/66045327867.pdf
    • http://pngroup.pl/ckfinder/userfiles/files/javafukivofapolisumataba.pdf
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609d6def9f38c---14862000373.pdf
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607d0f24baa86---17297454316.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=class+10+political+science+chapter+5+notes
    • 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_off0000f1b8.bin
bf9caf5e69570f624adc5cd0e0afb4bc99102db7c6712055116cb3915177f820
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B8 10812 bytes
font_01_sfnt_off00010aa8.bin
c32b7806e3c79b4f790f9a290ae837171e01536d739610a1a2d062b1860a6eb5
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AA8 16480 bytes
font_02_sfnt_off0001354d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1354D 16792 bytes