Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf2b2bac3a75670c…

MALICIOUS

PDF

84.4 KB Created: 2021-09-18 17:46:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e66bac385ef6bdb882508e2437fbf086 SHA-1: 8498244d042604fd026b66c7db3082e1b34bf3db SHA-256: cf2b2bac3a75670c9cc6a27158ad8de592b8c7e4488e1e7c766c6b898339c6d6
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external links, many pointing to other PDF files hosted on a variety of domains, with several heuristics flagging it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of external links suggests an attempt to redirect the user to malicious content, aligning with spearphishing attachment tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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.
  • 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 http://tubelessons.net/cms_images/file/48980470993.pdf In PDF document text
    • http://studioriboldi.eu/userfiles/files/91468721829.pdfIn PDF document text
    • http://studioghittigargnano.com/userfiles/files/finutafineromuri.pdfIn PDF document text
    • https://transport.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/92021363208.pdfIn PDF document text
    • http://live-net.it/file/lovajadowifidokarujebi.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/a331f6233bcc0f6a293eda0a7b881a02/60679228929.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/zuruzuwu.pdfIn PDF document text
    • http://gocoachfox.com/userfiles/file/57988424329.pdfIn PDF document text
    • https://emartdeko.pl/galeria/file/54940920176.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/wuxewe.pdfIn PDF document text
    • http://nenayu.com/filespath/files/20210907071400.pdfIn PDF document text
    • https://vleek.com/uploads/files/61050289515.pdfIn PDF document text
    • https://srilangkapools.com/contents/files/jarowidaf.pdfIn PDF document text
    • http://ailizia.com/userfiles/71536504777.pdfIn PDF document text
    • https://magnanerie-cazilhac.com/userfiles/file/rofovuzu.pdfIn PDF document text
    • http://lightningriskassessment.com/ci/userfiles/files/79371005775.pdfIn PDF document text
    • http://palmdale.thepokeluau.com/uploads/files/53862993152.pdfIn PDF document text
    • http://elitaliaweb.it/upload/file/roded.pdfIn PDF document text
    • https://salonrewards.ca/images/file/83013384086.pdfIn PDF document text
    • http://clerus.hu/files/file/37404680591.pdfIn PDF document text
    • https://learnrkbin.jugalbandiresearch.com/ckfinder/userfiles/files/30691295074.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613065629615f---nifogejoz.pdfIn PDF document text
    • https://gencerenerji.com/resimler/files/nisas.pdfIn PDF document text
    • https://vjlabor.pitscovn.com/uploads/Upload/files/87764980862.pdfIn PDF document text
    • http://93564497.com/userfiles/21877542803.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=streaming+mnf+live+freePDF 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_off0000e573.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE573 10412 bytes
SHA-256: 26d5a2f9546bf0ebbc20fd98b1358b1f48ce39ae4f9a49635e4e353911287f7d
font_01_sfnt_off0000fd07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD07 17980 bytes
SHA-256: cf9be74c62904a94c0b07eb3c9543370f44b910f4638030cb3b268c32df08fbd
font_02_sfnt_off00012bd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BD7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1