Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3440b9e4f1251de…

MALICIOUS

PDF

75.5 KB Created: 2021-09-28 04:01:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 7f532f4f6a3be27fa77fa7e661cee8b4 SHA-1: 6f247064dc372b373a3a53f085e785d6cc2076a9 SHA-256: f3440b9e4f1251ded02774f5f98dc831eab6edb9910893a20ecd8ec29191614d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the structure and URL patterns are consistent with malicious PDFs that may leverage embedded JavaScript for obfuscation or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://stolizstekla.ru/userfiles/file/26870088737.pdf In PDF document text
    • http://soundspace.eu/Upload/file/jodawezakabeb.pdfIn PDF document text
    • https://www.tahitotfaluovodak.hu/ckfinder/userfiles/files/kukukekivimeferek.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/a39c19accec44abc671b3d65e9e6a4e2/dijimagebol.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/161447bffcf94f---34902241967.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d4747278fd---39905971204.pdfIn PDF document text
    • http://poiskvod.ru/images/file/zoxipibopux.pdfIn PDF document text
    • https://dasyueshan.org/userfiles/file/70990821932.pdfIn PDF document text
    • http://lutechmed.com/Images_upload/files/19934895198.pdfIn PDF document text
    • http://kingsbrite.com/kingsbrite.com/userfiles/file/30434326372.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614757214ef19---74408494558.pdfIn PDF document text
    • http://dotbamboo.com/file_media/file_image/file/tedofekenel.pdfIn PDF document text
    • http://flexinform.com/hirlevel/file/keben.pdfIn PDF document text
    • http://ulv-fogger.es/d/files/59631731986.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/94813018238.pdfIn PDF document text
    • https://pianotuningdarwin.com/userfiles/files/9798445706.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/c70ce3f4632ce63bda5782bed77faa64/73397324142.pdfIn PDF document text
    • http://arcenevents.nl/site/upload/files/poxoritezumumazekusokunup.pdfIn PDF document text
    • http://www.focitabor.hu/userfiles/file/womitonirubozowamagi.pdfIn PDF document text
    • https://inunekocp.jp/mailmagazine/upload/files/zorizijumativepenalifoluv.pdfIn PDF document text
    • http://americansemitruckparts.com/d/files/42155339489.pdfIn PDF document text
    • http://albertopizzetti.it/userfiles/files/21587649184.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/6969428bf763e072a3a468027c11eb40/76160313849.pdfIn PDF document text
    • https://yaofangpeixun.com/upload/files/dowaxosagolerodol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=rogue+trader+soul+reaver+pdfPDF 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_off0000bed0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBED0 18656 bytes
SHA-256: c5b4e7fc2f7779e70c0c86c5081b389dbe0e2ec34dd956798dfd97f9b29f3ecc
font_01_sfnt_off0000ef5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF5F 10688 bytes
SHA-256: e7f55be4f4f44fb939e5444ec503ea8eebcec5207ff4edd9a71a04b9bb415c1b
font_02_sfnt_off000107f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1