Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8c4efab9f0cd586…

MALICIOUS

PDF

67.9 KB Created: 2021-09-16 04:36:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: aaafc6e5985b95ca044b0a85804467fd SHA-1: 17fa293b67e13ea37d9f207fa5db165a3d11b56f SHA-256: f8c4efab9f0cd586e210f8fec36bbdae7777eab4d394ba47d0881d21f66e56b3
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and is flagged as a phishing lure due to its small size and image-only content, typical of a screenshot that hides a clickable action. The document body is heavily obfuscated, but the presence of JavaScript and numerous external URIs suggests an attempt to redirect the user to malicious content or download a payload. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 67 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://aprt1day.ru/file/sodidomilirut.pdf In PDF document text
    • http://viorina-deko.com/images/file/51208941548.pdfIn PDF document text
    • https://mywayrtk.com/userfiles/file/29017793701.pdfIn PDF document text
    • http://satunatc.ac.th/ckfinder/userfiles/files/71455068049.pdfIn PDF document text
    • http://devison-matras.com/upload/file/67498216914.pdfIn PDF document text
    • http://w3-japan.com/js/upload/files/pezuba.pdfIn PDF document text
    • http://www.pes.edu.mn/ckfinder/userfiles/files/xazuwexukimawa.pdfIn PDF document text
    • http://eubeer.vn/uploads/files/dilabolezoxokivaz.pdfIn PDF document text
    • http://irs-messtechnik.at/upload/xukerozesobubokuxi.pdfIn PDF document text
    • http://pngroup.pl/ckfinder/userfiles/files/44987361749.pdfIn PDF document text
    • http://morard-mcf.fr/data/Files/83481372505.pdfIn PDF document text
    • http://dlastudenta.org/Upload/file/zusamuga.pdfIn PDF document text
    • http://stnicholasway.com/userfiles/file/96891804188.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/32300975864.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/abg5el3pjofumfk0qgfn6scho1/99611908074.pdfIn PDF document text
    • http://klaaswester.nl/img/file/zijeboz.pdfIn PDF document text
    • http://ashole.hu/UserFiles/File/buziw.pdfIn PDF document text
    • http://baby-daycare.com/uploads/files/202109120405552846.pdfIn PDF document text
    • http://bookblog.kr/data/file/files/44354743325.pdfIn PDF document text
    • https://vgcanada.com/userfiles/file/bazifekepujexiki.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/ju1h4tcdr84cumm8otm8ahvne7/48195267708.pdfIn PDF document text
    • https://hfbee.tw/upload/ckfinder_temp/files/20210908153114.pdfIn PDF document text
    • http://krakow4you.pl/krakow/files/muwujagitipekemesanatij.pdfIn PDF document text
    • http://hai-bi.com/uploads/files/202109070644056919.pdfIn PDF document text
    • http://around-sicily.net/userfiles/file/49948558801.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=need+for+speed+rivals+download+apkPDF 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_off0000b00d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB00D 13792 bytes
SHA-256: 3004573891eb2e8df45e9954e776c30ae1e2324ecb4a86a24d4c8c4e3fee06b6
font_01_sfnt_off0000d1bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e9d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9D6 10612 bytes
SHA-256: db817833db676a4817722bd011df6b639a4dcd808d3670b912b11fa6a954be9d