Malicious PDF — malware analysis report

Static analysis result for SHA-256 91685332ac860bd7…

MALICIOUS

PDF

71.0 KB Created: 2021-10-05 15:48:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 8c517be2b0dd6f18dc0dde561f41d2be SHA-1: cbccde697f739b67ed3152e6e1094ca1ff812d64 SHA-256: 91685332ac860bd73ce768040a9846e4f9388b23416668a78a4a977d6317b3c3
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by multiple heuristics and a machine learning classifier, with ClamAV detecting it as Pdf.Phishing.Trojan. The file contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these links indicates an attempt to lure users to external sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://huntic.ru/uplcv?utm_term=voiced+and+voiceless+sounds+examples PDF link annotation
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/ok5eu4qph58boinj7ovk2slumm/wibetonuke.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613926364c4be---dudojej.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137d30b3a6d6---tatepuketetevimubini.pdfIn PDF document text
    • http://solmoda.it/userfiles/files/93481594753.pdfIn PDF document text
    • https://traveletrust.com/basefile/traveletrustcom/files/xovumuro.pdfIn PDF document text
    • https://www.tyrtaios.gr/ckfinder/userfiles/files/tatitipanaz.pdfIn PDF document text
    • http://khocabien.com/uploads/files/nejig.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/gazowaset.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/81773896440.pdfIn PDF document text
    • http://renknh.com/ckupload/files/duxewokexatopugak.pdfIn PDF document text
    • http://hun777.hu/_user/file/76570789145.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/hef9mgdf59shhidih5u1lnci7q/65494756772.pdfIn PDF document text
    • https://vzglavniki.net/data/file/8064189785.pdfIn PDF document text
    • https://apsco.ly/userfiles/files/zivituwekazujanud.pdfIn PDF document text
    • https://rodolphe-blanchet.fr/Rodolphe/fckeditor/file/44234664985.pdfIn PDF document text
    • http://rakuteriyakicanogapark.com/uploads/files/dosapaluxelixefujojenuxiw.pdfIn PDF document text
    • http://lpc2529.com/piceditor/file/20825359578.pdfIn PDF document text
    • http://beijingteye.com/upload/files/biweg.pdfIn PDF document text
    • http://sanxuatbanthinghiem.org/app/webroot/uploads/files/zuliregowitubas.pdfIn PDF document text
    • https://lrsdev.com/userfiles/file/82691418383.pdfIn PDF document text
    • https://longhoang.vn/upload/files/tudupixikeganagamojaditiz.pdfIn PDF document text
    • https://nileagriculturalindustries.com/file/44395073912.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/10489383793.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_off0000b288.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB288 17084 bytes
SHA-256: 830ebf3f6e97952264707da98930b93dc4b265cf2624e6545836ec5ae290bf53
font_01_sfnt_off0000de10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE10 10712 bytes
SHA-256: 65b4e5ed514ed7485203fda2abfc576d5afd2aea539878024f361a429a8b4bd5
font_02_sfnt_off0000f6ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6AB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1