Malicious PDF — malware analysis report

Static analysis result for SHA-256 177837329032a5bf…

MALICIOUS

PDF

93.1 KB Created: 2021-09-20 07:37:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 98cac7ba6927036c08b42ceca91b57f2 SHA-1: 9e28c44e0188884470aad67563f8cfa95fdb3363 SHA-256: 177837329032a5bf0d2fcac94408202cf50383994f75e04b1618b04d4bb1c660
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests it's designed to lead users to external, potentially harmful, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://krisoc.ru/uplcv?utm_term=a+map+of+days+pdf+free PDF link annotation
    • https://abisspaandboutique.com/nbloom/fckuploads/file/wesog.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613469d3df36d---tisujovofetowuzalosazexe.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210902155512.pdfIn PDF document text
    • https://leresto-niort.fr/images/userfiles/files/27356696685.pdfIn PDF document text
    • https://namratalakhotia.com/userfiles/files/jipapuzel.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/81591137350.pdfIn PDF document text
    • https://b2bircruise.travflex.com/bot/ckfinder/uf/files/26047321657.pdfIn PDF document text
    • http://agrihitech.net/media/ftp/file/jezuri.pdfIn PDF document text
    • http://proxima-design.cz/files/file/60670711315.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/4vhhg0eg92qf4aktmb8k66k3u4/lukudesixon.pdfIn PDF document text
    • http://hospitalityroyal.com/upload_files/file/gokibixegatuniz.pdfIn PDF document text
    • http://boletin.alicantehosteleria.com/lib/ckfinder/userfiles/files/wagifofijipibu.pdfIn PDF document text
    • http://p-jtech.com/userData/board/file/60205045216.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/79f3636f2af3424e09cfa90d1c513c63/xofurib.pdfIn PDF document text
    • http://elturo.ru/img/upload/files/28089181249.pdfIn PDF document text
    • https://eniedu.com/data/file/20210914050913.pdfIn PDF document text
    • https://perkunasstudio.com/uploads/files/202109090749332635.pdfIn PDF document text
    • http://modulobase.com/userfiles/file/1569717999.pdfIn PDF document text
    • http://balletpanov.com/uploads/files/dutobevexuzu.pdfIn PDF document text
    • http://jumpstart.mobi/ckfinder/userfiles/files/57943816765.pdfIn PDF document text
    • http://diegogenna.it/userfiles/files/61146626494.pdfIn PDF document text
    • http://gaytonfa.com/upload/files/2896659273.pdfIn PDF document text
    • https://abrasco.org.br/ckfinder/userfiles/files/52214714646.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dba4bc9447---9298328026.pdfIn PDF document text
    • http://hophungvietnam.com/app/webroot/uploads/files/zifewegubi.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_off000109e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109E0 17604 bytes
SHA-256: 730942b60ccfb3c6c8a5678f5d2a336c2e713f3ba7781dc1b5fa389c9d58b008
font_01_sfnt_off000136d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136D2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014ee9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EE9 10412 bytes
SHA-256: 2dbb447bb441985459c352ecbc56292affa3bea54bd65a5a7f388e37bd917ee2