Malicious PDF — malware analysis report

Static analysis result for SHA-256 f661073c4c37fa3e…

MALICIOUS

PDF

81.3 KB Created: 2021-09-19 09:08:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1f64ea6deaa2a81e535acb5c175f57e0 SHA-1: 1b89beef37108d2308af3e984d1a7ed07a0afb52 SHA-256: f661073c4c37fa3e0346e5ec2bd1adc820c05a0b1a3315206b90e4b77b7b4db9
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, and it contains embedded JavaScript. The presence of numerous external URIs, many of which appear to be part of a link farm on disposable hosting, strongly suggests a phishing or malware distribution attempt. The embedded JavaScript likely facilitates the redirection or download of malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9780

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
  • 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://inwebjor.ru/uplcv?utm_term=footbal+manager+android PDF link annotation
    • https://jjcfurnituremaker.com/userfiles/files/1987590344.pdfIn PDF document text
    • https://fishboat.hr/files/jedubanijafazeniz.pdfIn PDF document text
    • http://saipanbooking.com/FileData/ckfinder/files/20210919_175C9390D32BF9DF.pdfIn PDF document text
    • https://isuzuphonoi.com/data/dulieu/files/56409023551.pdfIn PDF document text
    • http://eminenceinc.com/userfiles/file/73977425870.pdfIn PDF document text
    • https://binhvi.com/upload/files/33989597189.pdfIn PDF document text
    • http://kuryakyn.ru/userfiles/file/79413107612.pdfIn PDF document text
    • http://lexuspolymers.com/assets/ckfinder/userfiles/files/96841554003.pdfIn PDF document text
    • http://abwclayton.com/uploads/files/37348709167.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/pepovika.pdfIn PDF document text
    • https://remini.hu/userfiles/file/lojabekaxirewo.pdfIn PDF document text
    • http://twfbs.com/ckfinder/userfiles/files/42710038842.pdfIn PDF document text
    • http://malir-naterac.info/UserFiles/File/sovesezojak.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/e3aaf702c04a3723b82532a122ebd1a1/54905799442.pdfIn PDF document text
    • http://www.portofmiamitunnel.com/system/js/back/ckfinder/userfiles/files/82454838964.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16142602e2a03b---92159124073.pdfIn PDF document text
    • http://batterseataxi.com/survey/userfiles/files/90553068687.pdfIn PDF document text
    • http://bookblog.kr/data/file/files/jojirodix.pdfIn PDF document text
    • http://dotacjedlaoze.pl/userfiles/file/68846404856.pdfIn PDF document text
    • https://fonixkoncert.hu/upload/file/7516941330.pdfIn PDF document text
    • http://espacioschillout.es/images/admin/file/pejizi.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/4021210006131bc04dc8c9.pdfIn PDF document text
    • http://domplus.su/userfiles/files/kafomofuxujurelulifap.pdfIn PDF document text
    • https://gruppopolidori.com/upload/image/file/84749878490.pdfIn PDF document text
    • http://ideatity.com/ckfinder/userfiles/files/11652852903.pdfIn PDF document text
    • http://longtra.vn/userfiles/file/18555572322.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000be55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE55 18348 bytes
SHA-256: 5d82eca9b914137365405cdf46367a76bf5a696b52140a7dfb507ae49d48efe1
font_01_sfnt_off0000daad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAAD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f2bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2BF 17236 bytes
SHA-256: bf399a38a4b689cf4540b4c9d6974211a93ae25c348477383d1c2c8836d92c37
font_03_sfnt_off00011f20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F20 10540 bytes
SHA-256: 4651e7bd5cdf77bf6e15ea586c55fa462e761ad08749301b78368acc8e3cbef2