Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a653e8998cf2f20…

MALICIOUS

PDF

68.7 KB Created: 2021-09-25 07:26:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 27072d9f700874527b3e5d42f7292971 SHA-1: 530bc42a9f8139358efb4fd35ad15f7aab948a18 SHA-256: 8a653e8998cf2f203bed9cad62aa19c8d9d9870cc396a0e759fdba91ec2af8cc
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document that contains embedded JavaScript and numerous external links. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates that the PDF is a link farm on disposable hosting, suggesting a phishing or malware distribution attempt. The embedded JavaScript likely facilitates the redirection to these malicious URLs, which are designed to appear as legitimate files but lead to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://medvor.ru/uplcv?utm_term=windows+8+new+product+key PDF link annotation
    • http://kaitianjinghua.cn/admin/userfiles/file/202109151458396929.pdfIn PDF document text
    • https://idealist.ro/userfiles/file/61466489370.pdfIn PDF document text
    • https://777mto.info/contents/files/fibip.pdfIn PDF document text
    • https://lotusmarinevn.com/upload/files/32855904079.pdfIn PDF document text
    • http://www.moyekolodin.com/files/kujunatawinaxizewizopij.pdfIn PDF document text
    • https://eko-briketes.lv/userfiles/files/53313162431.pdfIn PDF document text
    • http://reguitti-engineering.it/userfiles/files/jodok.pdfIn PDF document text
    • http://engroupe.ca/aym_image/files/xonavudemuwob.pdfIn PDF document text
    • http://101-games.ru/images/uploads/files/fefidabiz.pdfIn PDF document text
    • http://clinicaveterinariacittadivignola.com/userfiles/files/leneted.pdfIn PDF document text
    • http://tavio.su/files/file/11726334040.pdfIn PDF document text
    • https://kimansion.com/uploads/file/kopese.pdfIn PDF document text
    • http://machinegroup.ru/img/outer/files/54823137733.pdfIn PDF document text
    • https://uetty.xyz/js/ckfinder/userfiles/files/38352470569.pdfIn PDF document text
    • https://daaeportrett.no/upload/file/82618002299.pdfIn PDF document text
    • https://perfecthospital.org/FCKeditor/file/10717665792.pdfIn PDF document text
    • http://seosanhrd.com/userfiles/file/deviraz.pdfIn PDF document text
    • http://sasnowosielski.com/ckfinder/userfiles/files/gomomimemiminuxuba.pdfIn PDF document text
    • http://chronocertif.com/userfiles/file/21945487733.pdfIn PDF document text
    • http://cokhilegia.com/upload/files/40538375849.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/db3dc557771948d0ec20bf3fedc89af3/banivobujigowowos.pdfIn PDF document text
    • http://kondicionery-domodedovo.ru/upload_picture/file/11880618453.pdfIn PDF document text
    • http://arabic.cz/ckfinder/userfiles/files/7635230231.pdfIn PDF document text
    • https://betentour.com/sites/default/files/file/wivubuse.pdfIn PDF document text
    • https://martas.vodrsport.cz/uploads/files/nadojuretadiravir.pdfIn PDF document text
    • http://dierenwinkelindex.nl/images/uploads/dukokelepiwosaj.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_off0000b008.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB008 14400 bytes
SHA-256: 4d5456382f7fcc5dbe214c0b03c0e27c01f5291e206c4e76e6595fb5d0243c0c
font_01_sfnt_off0000d3cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3CB 10892 bytes
SHA-256: 7a633fd2204c092c4f0d5b85b7330cc9030dd190ffc7a8593c151c4e926f38f3
font_02_sfnt_off0000ed3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED3F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1