Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fcdc038d22dce07…

MALICIOUS

PDF

71.3 KB Created: 2021-09-29 10:15:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 638a97bd6099d5c52e1d393978fe6075 SHA-1: 9366323c707d1764a78c01bb741b405f708a1169 SHA-256: 8fcdc038d22dce075f9c3542be6035186d875c4b7b04ed91f210d5bf21f8079e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code within documents. It also features a link farm pointing to various domains, including one that appears to be compromised WordPress upload storage. These elements suggest the PDF is designed to lure users to external sites, likely for phishing or to download further malware. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://inwebjor.ru/uplcv?utm_term=wifi+brute+force+attack+software+windows PDF link annotation
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613f7a5c48ffa---41463147440.pdfIn PDF document text
    • https://menuiserie-sainte-anne.fr/userfiles/file/77921834415.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/2ad17536630399c4159d84bddd061e0b/vewapolidamarewawuz.pdfIn PDF document text
    • https://lmetinternationalschool.in/ckeditor/ckfinder/userfiles/files/22861062856.pdfIn PDF document text
    • http://capitaloffice.pl/fotki/file/5509039099.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/54252708658.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/tafunewakuroximaweje.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1615401335f8f9---wupewegajujetubas.pdfIn PDF document text
    • http://langmoon.jp/js/upload/files/nuzevoxusiletinegekegu.pdfIn PDF document text
    • http://2017.letnifestiwal.pl/ckfinder/userfiles/files/31848266121.pdfIn PDF document text
    • http://pentas.eu/userfiles/file/fuvapadodevewi.pdfIn PDF document text
    • http://tagsu.com/attachments/fckattachments/file/kuripefivikolazuvujip.pdfIn PDF document text
    • http://www.pibmg.com.br/ckfinder/userfiles/files/files/96529206111.pdfIn PDF document text
    • http://2015.letnifestiwal.pl/ckfinder/userfiles/files/904702732.pdfIn PDF document text
    • http://a-swiss.com/upload/userfiles/file/zegonupekugub.pdfIn PDF document text
    • http://muabannhagiare.net/images/uploads/files/57247477742.pdfIn PDF document text
    • http://chukysovin.com/img-svc/files/gudifeluzut.pdfIn PDF document text
    • http://xn--82cac8d3ajrc0gd0bo4a7nf3qg.com/userfiles/files/1185858707.pdfIn PDF document text
    • http://zjgyuanhong.com/v15/Upload/file/2021929136413238.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/67643104280.pdfIn PDF document text
    • http://virtuozi.ru/sites/all/sites/virtuozi.ru/files/9125730644.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/zugunudufos.pdfIn PDF document text
    • http://dekogard.net/deko/veri/_files/71682319155.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/pnhiidph7922068te2tgo6iv47/85951588151.pdfIn PDF document text
    • http://fujiya-la.com/uploads/files/xizodokatubu.pdfIn PDF document text
    • 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_off0000b270.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB270 10836 bytes
SHA-256: 71f6d21dd182da3664b43af89e02623f12cc404339e3c73ee320c78af4bbe259
font_01_sfnt_off0000cbac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBAC 16612 bytes
SHA-256: 590c07f85d246811ccbccc7db64c56075ef7b2d8259778b2b63d6b19fb01c040
font_02_sfnt_off0000f586.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF586 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1