Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5ef32d4f3c95f74…

MALICIOUS

PDF

96.4 KB Created: 2021-09-16 04:11:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 638ac805652bd7bb5afe3f7fe61a3883 SHA-1: aa707ad429ddb23863944f170f9318c19dd69537 SHA-256: f5ef32d4f3c95f74d2cd100b024908e4d9bb29b9badc9af7dd1e6f5cdff7403a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to PDF files hosted on potentially disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to serve as a downloader or redirector for further malicious content. The presence of embedded JavaScript suggests an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

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 http://aranykoronakft.hu/userfiles/file/tobenari.pdf In PDF document text
    • http://xinyaoqiye.com/upload_fck/file/2021-9-14/20210914133001432720.pdfIn PDF document text
    • http://regalmotors-jp.com/js/upload/files/siwimovixipaxofaze.pdfIn PDF document text
    • http://hzosm.com/images/upload/File/limukevogipimo.pdfIn PDF document text
    • http://canxetaidientu.com/images/file/50323684216.pdfIn PDF document text
    • https://www.gullyracing.it/admin/ckfinder/userfiles/files/debiloletovubezugaw.pdfIn PDF document text
    • https://csn-alliance.com/data/files/6293821627.pdfIn PDF document text
    • http://wxbeimei.cn/upload/ckimg/files/202109130558242715.pdfIn PDF document text
    • http://culfordequestriancentre.org/UserFiles/file/zanonoxoranelufakut.pdfIn PDF document text
    • https://knurussian.kr/DATA/upload/files/202109131944345182.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/16557846388.pdfIn PDF document text
    • http://ailizia.com/userfiles/soziwot.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/161313eb013fc7---nokevakik.pdfIn PDF document text
    • http://gddfboiler.com/uploads/files/nekusewodadiwo.pdfIn PDF document text
    • https://worldcastlive.com/userfiles/file/jujamun.pdfIn PDF document text
    • http://www.mamafoundation.cz/ckfinder/userfiles/files/wevanomojuwibe.pdfIn PDF document text
    • http://mientaytourist.com/uploads/files/85483861732.pdfIn PDF document text
    • http://ydyb.com/filespath/files/20210916083314.pdfIn PDF document text
    • http://tbvshungviet.com/upload/files/89090089508.pdfIn PDF document text
    • http://sovaimm.it/userfiles/files/46092122728.pdfIn PDF document text
    • http://boonfagrandhome.com/user_img/files/moxulilek.pdfIn PDF document text
    • https://dalba.net/other_files/File/nikojelefazexinadosu.pdfIn PDF document text
    • http://mamitobe.ru/files/file/19777083687.pdfIn PDF document text
    • https://cardion.dk/gfx/fckimages/file/3332417899.pdfIn PDF document text
    • http://ossokahve.com/upload/file/jewikutapozal.pdfIn PDF document text
    • http://acm-medicali.it/userfiles/files/65271767684.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=words+that+start+with+f+and+end+with+k+four+lettersPDF 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_off00010750.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10750 23116 bytes
SHA-256: 26d1062de33c8bc7db9b103ffadd0bba0a07bb99e23c6953df504686195c1825
font_01_sfnt_off000142ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142AC 10724 bytes
SHA-256: 91a8fea654c7a3701ef395d0727e9fd4c4e52db2559ec41da523a9e695358f6a
font_02_sfnt_off00015b4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1