Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca5cad3bd970d6c0…

MALICIOUS

PDF

77.1 KB Created: 2021-09-01 19:26:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 1c27e97e07ab87994e8b3a1095d7ab52 SHA-1: 50b71994f274d627d6dd1b1e017040a7d36421ce SHA-256: ca5cad3bd970d6c05fe666f0bd7d36b56ff2e941479b95fb4eba9f9237ec162e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to compromised websites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for human readability but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://smidgel.ru/uplcv?utm_term=silly+crossword+clue PDF link annotation
    • https://mmgrowersg.com/ckfinder/userfiles/files/tegero.pdfIn PDF document text
    • https://fotokeramika.bg/userfiles/file/xebinemolog.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/2bs9cj4s778is9vkc05c87aohn/vukagidemubonejorisa.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/160785ee720d8e---nidadapefadikurawedoka.pdfIn PDF document text
    • http://mega-treid.com/userfiles/files/topokegu.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/79832555287.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16077397bf13bd---59628545920.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-5-27/20210527213747976486.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c925dcb4f9f---nepopolari.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/62622874346.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b30cae933fa---40685343367.pdfIn PDF document text
    • http://td-mg.ru/uploads/files/wamonerebosus.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/9a587f9fd6fa4bb49e7e33024f925c66/jovinidibo.pdfIn PDF document text
    • http://php-lounge.de/userfiles/file/fobinawesesafatagebe.pdfIn PDF document text
    • http://zonwering-belgie.com/ckfinder/userfiles/files/wizadixakivuxobuvimijumug.pdfIn PDF document text
    • https://scalper.ir/data/files/file/pexewesujalunujezivepafuz.pdfIn PDF document text
    • http://manixcnc.com/ckupload/files/lafamafibonudu.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/b6d1b80bf000f89d9b06c695f9074c47/zasitaxu.pdfIn PDF document text
    • http://casadiriposomarsala.it/userfiles/files/19320557159.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf4114a504---pijut.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/197469ecd310ea172edb508b0b1490fc/tufapigatokopovojexofu.pdfIn PDF document text
    • https://angelsforwarriors.org/userfiles/files/17532762546.pdfIn PDF document text
    • http://innovad-ltd.com/userfiles/file/75742874336.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_off0000cb69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB69 16716 bytes
SHA-256: 0c8e429ce8ac16962a92b1815853ec8d20c4d7baa42a4d97faee6fe11695289e
font_01_sfnt_off0000f6bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6BB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ed2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ED2 10376 bytes
SHA-256: d2568c3136dfacceaf456fc9fb946ff4c0282152a61d74ebfaa8b514ba8bd6f3