Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd11afda371e158a…

MALICIOUS

PDF

90.2 KB Created: 2021-09-12 03:35:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 953c6b3a1a2031b0c5318217e028234e SHA-1: 16cc2025be14cefce0d50db1e25463aafc388bc8 SHA-256: bd11afda371e158a6e177e0e1acee54662c62caccc631b8ee56d00921a50f671
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, suggest 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 direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://pixomot.ru/uplcv?utm_term=como+navegar+na+deep+web+pelo+android PDF link annotation
    • http://duancanhotot.com/upload/files/46379793682.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/1mjtveql7888oou7b471olpbfr/jurikekowumomo.pdfIn PDF document text
    • http://intranet.uts.edu.co/portal/app/ckfinder/userfiles/files/xomimezokorefoxofidedoboj.pdfIn PDF document text
    • http://kammerchor-lindau.com/file/vamobok.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/ohoo157brl9sriht9u2drk3lrq/bobufidorajapoburajiriz.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161343deca8f55---vanatemuvavobiseri.pdfIn PDF document text
    • http://orenprom.com/img/account/file/libel.pdfIn PDF document text
    • http://mmbc.cz/_data/user_files/file/bijirimefusifaxe.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/fipelapixezalumegami.pdfIn PDF document text
    • http://pataibicaj.hu/userfiles/file/jexupimubugalimoki.pdfIn PDF document text
    • http://linza-market.ru/upload/files/wofujogesewakak.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613389921f5e2---59726195088.pdfIn PDF document text
    • https://specializzati.tecnaevolution.it/dataload/ckupload/79283586404.pdfIn PDF document text
    • http://lightningriskassessment.com/ci/userfiles/files/4327624506.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/pimawesixifu.pdfIn PDF document text
    • http://tlw.ro/UserFiles/file/5436862591.pdfIn PDF document text
    • http://www.extramas.com/userfiles/files/watazikedixu.pdfIn PDF document text
    • http://usateatop.com/_upload/files/27443281968.pdfIn PDF document text
    • http://strandedtattoo.com/file/zurifaxurepasozinevixu.pdfIn PDF document text
    • http://www.serge-valentin.net/ckfinder/userfiles/files/resogamakiloburagire.pdfIn PDF document text
    • https://tybistanbul.org/resimler/files/nafisakaxu.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_off0000fb6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB6A 10792 bytes
SHA-256: 52a78ed8b4b3282e6bd61750f4684d037328d072c1f9b1bb94fd09f17ac4984e
font_01_sfnt_off000113c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113C8 18176 bytes
SHA-256: 0896f03a829fdc49f004d051ccdcbc4c02f1afa3d59b34f64c33c14c9a58b7bb
font_02_sfnt_off000142f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1