Malicious PDF — malware analysis report

Static analysis result for SHA-256 421f9da44635e3f5…

MALICIOUS

PDF

82.4 KB Created: 2021-09-17 06:19:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c22a75ba1fd34a4a553d792c5c24ecad SHA-1: 8d7c5063696510e2dfb48609baccedeea441674b SHA-256: 421f9da44635e3f549e8f6a3f977dc4e733b42f677bb57ae6fc9ae4c93b95bb3
234 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and multiple external links, flagged by ML classifiers and ClamAV as malicious. Critical heuristics indicate it's a lure for recovery secrets or private keys, and also suggests a password-protected archive handoff. The embedded JavaScript likely facilitates the execution of a malicious payload or redirects the user to a phishing site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Recovery secret / private key request critical SE_SECRET_RECOVERY_LURE
    Document requests recovery phrases, private keys, backup codes, or saved passwords. Requests for these secrets in a document are high-risk.
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://bywuf.org/upload/editor/files/mepebagod.pdf In PDF document text
    • http://specialcats.nl/media/files/22863018803.pdfIn PDF document text
    • http://sciattella.net/images/file/xavat.pdfIn PDF document text
    • http://hoanggiaphatstone.com/upload/files/xijogov.pdfIn PDF document text
    • http://cortocircuito.trialpanel.com/images/Upload/files/34914005314.pdfIn PDF document text
    • http://dakmoto.cz/obrazky/file/2831309892.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-8/20210908001347203008.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/fabozakasesofomuba.pdfIn PDF document text
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/43853247452.pdfIn PDF document text
    • http://thewellmanteam.com/userfiles/files/xatexeluxoxelodozebezi.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/5639671437.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/bivibido.pdfIn PDF document text
    • https://mercerapparelss.com/userfiles/files/67005597572.pdfIn PDF document text
    • http://lachambredechos.com/userfiles/file/73365882270.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140bddbf15b1---witeveb.pdfIn PDF document text
    • https://limsurempat.com/contents/files/50445057083.pdfIn PDF document text
    • https://get-insurance.in/ckfinder/userfiles/files/97052545110.pdfIn PDF document text
    • http://musclecar-taps.com/js/upload/files/mavuvewipabozikivad.pdfIn PDF document text
    • http://xsteelstock.com/d/files/gewalofa.pdfIn PDF document text
    • https://langumeistras.lt/i/File/74278104029.pdfIn PDF document text
    • http://kavtas.com/images_upload/files/6823411168.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///widuje.pdfIn PDF document text
    • http://greenlivinggarden.com/htdocs/UserFiles/file/34073106205.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/fixedujatizefinanug.pdfIn PDF document text
    • https://gifarlcm.com/upfiles/editor/files/54312918893.pdfIn PDF document text
    • http://lishasurgical.in/ckeditor/ckfinder/userfiles/files/velevurasanogezisujiger.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=digitally+sign+pdf+linuxPDF 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_off0000dd23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD23 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f53a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53A 10640 bytes
SHA-256: ef6692b5d0ee34e067a65ea504829578f316bd3c25224040a7482b73bc0a64a0
font_02_sfnt_off00010d83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D83 17936 bytes
SHA-256: bbed7e5ec09b7f0137fc4dfe6ced6478e8a285974b03eb7368e54b31ba5c65f7