Malicious PDF — malware analysis report

Static analysis result for SHA-256 a52c7dcd640bf4a1…

MALICIOUS

PDF

72.3 KB Created: 2021-09-25 02:55:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: eb217efc2a489a07449468c61e9a6c6d SHA-1: cd4f0753157a7ac6fd8be32e4566e55521564a7d SHA-256: a52c7dcd640bf4a123f4c8606d316c005a7d76a576e1af44d64984e1ff2a3deb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs and is flagged by ML classifiers and ClamAV as malicious. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for multiple links, suggesting an attempt to obscure the true malicious destination. While no scripts were explicitly extracted, the nature of the PDF and its embedded links strongly suggests it is used as a lure for phishing or to redirect to malware download sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://galenbio.com/images/upload/file/mibezemixanalupugezizexar.pdf In PDF document text
    • http://n3ss.ro/ckfinder/userfiles/files/82257034235.pdfIn PDF document text
    • https://yennenga.org/business_school/uploads/file/gukesimiwutapifevuz.pdfIn PDF document text
    • http://huarui-bio.com/upload/files/libepuwijuruvuxulitixom.pdfIn PDF document text
    • http://dija.lv/public/userfiles/file/xekamegove.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/somat.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613e00a6b225e---jogefikesosorenota.pdfIn PDF document text
    • http://spbi.cz/res/file/67672504508.pdfIn PDF document text
    • https://tvmreza.tv/ckfinder/userfiles/files/30617058360.pdfIn PDF document text
    • http://mid-europe-ex.com/images/blog/file/nasetixodozat.pdfIn PDF document text
    • http://dlugopis.kbo.pl/ckfinder/userfiles/files/24576489265.pdfIn PDF document text
    • https://www.tyrtaios.gr/ckfinder/userfiles/files/1408998602.pdfIn PDF document text
    • http://dc-a50e0b1dcb2e.breakthrough-nutrition.com/userfiles/files/sisulo.pdfIn PDF document text
    • https://techielingo.com/fck_uploads/files/dimudatutadijeso.pdfIn PDF document text
    • http://naosgym.com/userfiles/files/92978061324.pdfIn PDF document text
    • https://maftplayer.net/calisma2/files/uploads/romuvafataluwituri.pdfIn PDF document text
    • http://thegioichuyendong.info/app/webroot/upload/files/37369781061.pdfIn PDF document text
    • https://ls-machinery.com/uploadpic/files/202109121951102931.pdfIn PDF document text
    • http://carszana.com/image/upload/File/ruxaliguwowivufotesasolow.pdfIn PDF document text
    • http://mu-rrrc.com/userfiles/file/84472443636.pdfIn PDF document text
    • http://mclarenquartz.in/ci/userfiles/files/fajajovutitozibawujo.pdfIn PDF document text
    • https://rugsinc.in/UserFiles/files/6750026551.pdfIn PDF document text
    • http://kondicionery-himki.ru/upload_picture/file/delojenujuwopud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=roadrunner+for+androidPDF 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_off0000b321.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB321 10180 bytes
SHA-256: 56536c54d7aaa6464c9ac256c2bb4738c42cca685bc9c128c356abf30637d100
font_01_sfnt_off0000c9ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9FF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e211.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE211 19188 bytes
SHA-256: dadec731aa309151413787e0a7412cf22a7a3cb7e3802c23d2625cb989d1ccba