Malicious PDF — malware analysis report

Static analysis result for SHA-256 53cf578b5257899a…

MALICIOUS

PDF

73.4 KB Created: 2021-10-01 15:45:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 0941b749a783e9f74580b2c437ee9fb6 SHA-1: 5d5714b08f47bccaab04117d582face0bcb5c580 SHA-256: 53cf578b5257899abb067eea8bce83a526f1b1a3700db142b3b438a651107397
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. The PDF also contains numerous external URIs, many of which point to suspicious domains and are likely used to redirect users to malicious sites for phishing or further malware downloads. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://najemwroclaw.com/userfiles/file/xolosam.pdf In PDF document text
    • http://ykzn8.com/upfiles/editor/files/16871927882.pdfIn PDF document text
    • https://ipssecurityconsultants.com/ckfinder/userfiles/files/68890064344.pdfIn PDF document text
    • http://banglatalkies.com/dynamic-images/cms/file/zedabebovisasa.pdfIn PDF document text
    • http://infinijewelry.com/userfiles/file/pamarejoripepoloditerifim.pdfIn PDF document text
    • http://cachnhietcacham.vn/Images_upload/files/85358927144.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/bea251bd92884ec7a2464cf49ee90e7e/98486794439.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/24885908412.pdfIn PDF document text
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/87498468539.pdfIn PDF document text
    • http://www.greddy.com/admin/common/ckfinder/userfiles/File/muwijemusiv.pdfIn PDF document text
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/remenabovefudawixuzalun.pdfIn PDF document text
    • http://architetturaurbanistica.it/userfiles/files/dezusololetijuvudiwufutev.pdfIn PDF document text
    • http://i-harmonics.com/upload/files/96924908264.pdfIn PDF document text
    • http://111-orte.com/testarea/cwsCMSlight/media/files/fumesusuzojopebida.pdfIn PDF document text
    • https://xn--fiqa735be48e.com/upload/files/10161907959.pdfIn PDF document text
    • https://www.artikel238.nl/emmwebbit/resources/ckfinder/userfiles/files/towolufeferuravoji.pdfIn PDF document text
    • https://ksi-system.pl/editorfiles/file/tezopesitilafeniwogepuxal.pdfIn PDF document text
    • http://www.stsmcc.org/www/js/ckfinder/userfiles/files/rowogoxafirewemuli.pdfIn PDF document text
    • https://tbsva.org/Upload/files/20210923000209.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/60541969661.pdfIn PDF document text
    • http://japan-railpass.info/images/blog/file/tebotifosexokinin.pdfIn PDF document text
    • http://munnarteabungalows.com/userfiles/file/venupukipobum.pdfIn PDF document text
    • http://knowleangling.co.uk/ckfinder/userfiles/files/jesapigudufa.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/q11ft0ldpmuvgh7hcbhveas9jb/15712502769.pdfIn PDF document text
    • http://lutechmed.com/Images_upload/files/kimavubiba.pdfIn PDF document text
    • https://khanoomhoteli.com/basefile/khanoomhotelicom/files/62367615172.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=my+hero+academia+season+2+episode+14+dubPDF link annotation
    • 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_off0000b723.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB723 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF3A 11232 bytes
SHA-256: 7fd02222708d38dc60dfc69d10d33460e19c9501b28b62bd3f2330359ea104c3
font_02_sfnt_off0000e945.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE945 17988 bytes
SHA-256: 4895f99544a75d09443924b42e688105f476fe447cc680caf86911217392c7fc