Malicious PDF — malware analysis report

Static analysis result for SHA-256 5231c869ef345dea…

MALICIOUS

PDF

75.5 KB Created: 2021-09-13 01:49:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d1534b1fa36f292abdccd7786def6b35 SHA-1: d4eb7e4ec2e2c31b09f33c439e6e49428780f0eb SHA-256: 5231c869ef345deae713d46dcd2d6b478cfb87fbb775c51a7a972d934e1c4aeb
134 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript. The PDF also functions as a link farm, presenting numerous URLs that likely lead to further malicious content or phishing attempts. The embedded JavaScript is a strong indicator of a secondary payload download or execution mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://areopag.ru/sites/default/files/uploads/43008902578.pdf In PDF document text
    • https://newegys.egyseg.eu/ckfinder/userfiles/files/zibakew.pdfIn PDF document text
    • http://learnersdigest.org/userfiles/file/sijusedikisop.pdfIn PDF document text
    • http://finance-bulldog.cz/UserFiles/File/bisotepufoz.pdfIn PDF document text
    • http://dynamicyunnan.com/ckfinder/userfiles/files/62165556107.pdfIn PDF document text
    • http://www.vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/zulabalatepexewuvi.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/a9a85a455a32d07c031c95bb93fa6743/28424744245.pdfIn PDF document text
    • http://tauben-buchmeier.de/kleinberliner-schuetzen/userfiles/files/tigikesewaravojafopixakev.pdfIn PDF document text
    • http://fszhenjia.com/upfolder/e/files/20210904123258.pdfIn PDF document text
    • https://tch.lu/files/files/2842151114.pdfIn PDF document text
    • http://makairways.in/home/makairways2017/public_html/dowalumniusa/ckfinder/userfiles/files/fatabumomalopikazu.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///33713001516.pdfIn PDF document text
    • https://zohopinler.com/calisma2/files/uploads/noxemojemepidekobalopak.pdfIn PDF document text
    • https://abctranslink.com/ckfinder/userfiles/files/30408888460.pdfIn PDF document text
    • http://soyaksiesta3.com/userfiles/file/vufilufudetedam.pdfIn PDF document text
    • https://znalac.com/userfiles/file/90747885076.pdfIn PDF document text
    • http://aj-freight.com/ckfinder/userfiles/files/81383659048.pdfIn PDF document text
    • http://haitrungkim.vn/uploads/userfiles/file/86333997678.pdfIn PDF document text
    • https://keiba-like.biz/js/ckfinder/userfiles/files/53474296253.pdfIn PDF document text
    • http://abwsalisbury.com/uploads/files/76605931412.pdfIn PDF document text
    • https://booknowrentalimo.ch/userfiles/files/nefudero.pdfIn PDF document text
    • https://colegiumaniucarei.ro/ckfinder/userfiles/files/kafowozutotepavojivoteri.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=my+phone+keeps+doing+things+on+its+ownPDF 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_off0000c410.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC410 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC27 10648 bytes
SHA-256: c4fe31da3f491c74df41f46e7ac34153c3f22c0e09502a060785957e8a38746f
font_02_sfnt_off0000f459.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF459 17072 bytes
SHA-256: 188b7f6c59468cce74ae8a58b95e1cb92321a4f8f61fd640a701a62901b3d87e