Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f22a6cc17c0d899…

MALICIOUS

PDF

79.9 KB Created: 2021-09-18 12:52:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: b916083e85e0accdf30f0f0805651127 SHA-1: 3c58449f753d7216597429d46948b38dc3d197ad SHA-256: 8f22a6cc17c0d899305db197d6f719f0de007154ea6a7fc2964787f016a67e1b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs, one of which is presented as a download link for 'cheetah keyboard apk', indicating a social engineering lure. The presence of multiple disposable link farm domains further supports a phishing or malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • 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.
  • 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://crewmak.ru/uplcv?utm_term=download+cheetah+keyboard+apk PDF link annotation
    • http://mauchlineware.com/html/chapelstreet/web/userfiles/files/mimimumen.pdfIn PDF document text
    • https://stdtekstil.com/upload/ckfinder/files/77313590332.pdfIn PDF document text
    • http://mamitobe.ru/files/file/90897755913.pdfIn PDF document text
    • http://moretonassets.net/userfiles/namuxoguvudod.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/10c36c7f4873fe4a83b451456fcf6a7b/87879015431.pdfIn PDF document text
    • https://behagi.eus/files/galeria/files/31875932369.pdfIn PDF document text
    • http://erfaspot.com/resimler/files/55188443027.pdfIn PDF document text
    • http://potentialdesign.cn/userfiles/file/1630699969.pdfIn PDF document text
    • http://hig-hegmann.de/userfiles/file/5497176459.pdfIn PDF document text
    • http://mnarch.it/userfiles/files/31525693617.pdfIn PDF document text
    • http://studiocastigli.eu/userfiles/files/85881151807.pdfIn PDF document text
    • http://xn--oy2b9bv81anouola.com/upload/file/202109180106009801.pdfIn PDF document text
    • http://bloemenwinkelindex.nl/images/uploads/nanope.pdfIn PDF document text
    • http://lamardaegu.com/upfile/user/file/sekinifiragusixuselati.pdfIn PDF document text
    • http://fredericjean.net/oplusco/file/butuzufapuwelevuzarusiz.pdfIn PDF document text
    • https://elitstroycraft.ru/source/file/sujubuwuwopubezenedas.pdfIn PDF document text
    • https://www.premiumtrade.ro/ckfinder/userfiles/files/89959401560.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/2664a95b5953e7bfde20b592018cf122/4879099112.pdfIn PDF document text
    • https://alarouba.com/ckfinder/userfiles/files/55832150467.pdfIn PDF document text
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/biloribexezenisat.pdfIn PDF document text
    • https://basalyemek.com/ckfinder/userfiles/files/xufosuvukusuleletab.pdfIn PDF document text
    • http://aquaclub.hu/userfiles/file/bunotazapefep.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/55304396011.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_off0000d5c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5C9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ede0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE0 10784 bytes
SHA-256: 6cac38744ab1b119d0c5dc670828804a891c0736c61685916618bfdc7da7d8b1
font_02_sfnt_off00010680.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10680 16924 bytes
SHA-256: 74779c8805de712d0e9cb0c18d31645569cd1842cd19649cac97e3fa42256073