Malicious PDF — malware analysis report

Static analysis result for SHA-256 52b7cadc65b49bf5…

MALICIOUS

PDF

69.2 KB Created: 2021-09-12 09:28:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dc88ab505938b6714fb43c9ae2286c91 SHA-1: 94bb50aa9023e13d9b0f7fc593ba3a98ea1fa8a3 SHA-256: 52b7cadc65b49bf5b1570d5193259d5f010d3cbc5533994f9fc5129a8208cd21
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and is identified as a phishing lure due to its small size and image-heavy content, typical of a screenshot designed to trick users into clicking a link. The document body is heavily obfuscated, but the presence of a PDF_RANDOM_URL_LINK heuristic firing indicates a link to an algorithmically-generated URL, likely leading to a malicious payload. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 69 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://www.tecnobor.com/ckfinder/userfiles/files/zemaviwosu.pdf
    • http://china-baby-clothes.com/d/files/muwudesa.pdf
    • http://medical-1669.com/userfiles/files/loragabirinawadok.pdf
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/7cbbfbe922e6cc89a76b0b237ec49ed4/31259255903.pdf
    • http://xn--b1afklwjc5g.xn--p1ai/ckfinder/userfiles/files/61979507551.pdf
    • https://ms02bet.net/contents/files/4272595338.pdf
    • http://dotbamboo.com/file_media/file_image/file/57481191853.pdf
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/65599191659.pdf
    • http://ambulatorioveterinariosantanna.eu/userfiles/files/22970100098.pdf
    • http://www.verneteco.com/ckfinder/userfiles/files/81075960383.pdf
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/16131bbbdcf55b---semaretozawobor.pdf
    • http://veterinariacasettamattei.it/userfiles/files/44091565504.pdf
    • http://cissi.it/userfiles/files/nuduzebale.pdf
    • https://meesens.be/KrMee/Tekstverwerker/42149420112.pdf
    • http://sieuthibongda.net/ckfinder/userfiles/files/85069004021.pdf
    • https://www.karelo.com/uploads/File/kadop.pdf
    • https://martabaktelor.com/contents/files/ximifipizotowawete.pdf
    • http://daisin1977.com/js/upload/files/17733918696.pdf
    • https://www.solucionaesp.com/ckfinder/userfiles/files/sotelenumazegipaxase.pdf
    • http://enewind.com/pliki/file/dugumubutejeko.pdf
    • http://factory-01.com/js/upload/files/15921598471.pdf
    • https://bywuf.org/upload/editor/files/47409378054.pdf
    • https://aradovan.com/userfiles/file/76715620547.pdf
    • http://furnitura-syndicat.ru/ckeditor/ckfinder/core/connector/php/uploads/files/fekapixafineb.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=fluid+mechanics+project+topics+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b32c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB32C 16792 bytes
font_01_sfnt_off0000cb43.bin
ce8627ec268970cc046bae701a9c4c8b3ac86d44450c2198af8befd74acc75ff
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB43 11092 bytes
font_02_sfnt_off0000e4d2.bin
29cddaba67b4d41b7e0f9cff54d9eab267c279a4e378342e09063a7cfc6bc6ed
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4D2 13908 bytes