Malicious PDF — malware analysis report

Static analysis result for SHA-256 b43c3f23974f272b…

MALICIOUS

PDF

67.5 KB Created: 2021-09-19 10:44:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: f397cf6f20dea842fd62f7107e5e21e5 SHA-1: bf421bb8646e6a3867cd9b5562e4253fba404b94 SHA-256: b43c3f23974f272b3874dfea8f7b2dcee03a73a458daacd437bf22e6c695f55e
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. The heuristics suggest it's an image-based lure designed to trick users into clicking an external URI, likely to download a second-stage payload. Embedded JavaScript streams are present, which could be used to facilitate the malicious action.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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 1 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://ciccioinpentola.com/userfiles/files/41570862139.pdf In PDF document text
    • http://xn--12cf1djdb6cbcafdbu1f1cudgcc8am4wf7htgd9de.com/ckfinder/images/files/81128534997.pdfIn PDF document text
    • http://xn--3bsx3iw22bmot.com/filespath/files/20210904063628.pdfIn PDF document text
    • https://episcopiaoradiei.ro/files/29230609579.pdfIn PDF document text
    • http://dainichiji.com/upload_ckr/files/23696201799.pdfIn PDF document text
    • http://shuimotongyuan.com/userfiles/file/56862515271.pdfIn PDF document text
    • http://brenderup.ro/mm/file/12197774484.pdfIn PDF document text
    • http://fc-junajted.com/upload/datoteke/70279236589.pdfIn PDF document text
    • http://qianxi.cn/filespath/files/20210904043528.pdfIn PDF document text
    • http://quimis.org/js/ckfinder/userfiles/files/fitodero.pdfIn PDF document text
    • http://oletrans.sk/editor_uploads/files/96005718957.pdfIn PDF document text
    • https://matricula.arendic.cl/files/74513111962.pdfIn PDF document text
    • https://fereshtegan.net/basefile/fereshtegannet/files/8530758193.pdfIn PDF document text
    • http://encino.ilovepokebar.com/uploads/files/vezenipunufujefunadimivul.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/af208cff8844f1f518225c18f75eecc8/xurazosufetatubaposemev.pdfIn PDF document text
    • https://mar3ol.com/Files/files/57171083783.pdfIn PDF document text
    • http://lactopad.com/uploads/files/38862241081.pdfIn PDF document text
    • https://atkarisuli.hu/userfiles/file/nujewodufixixagak.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/file/pupelokodugowexak.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/93753385909.pdfIn PDF document text
    • https://holcom-wd.com/webroot/img/files/44881849511.pdfIn PDF document text
    • http://bentleyplemtech.ru/userfiles/file/95676584188.pdfIn PDF document text
    • http://0048.pl/48files/file/wigozelaliz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=the+beginning+after+the+end+book+pdfPDF 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_off0000acb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACB9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c4cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4CB 14260 bytes
SHA-256: 71a4995cecf3edf8383beb764862fb7106a4f8a84e73b005923989e5fbc60800
font_02_sfnt_off0000e850.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE850 10756 bytes
SHA-256: 8716af35959c71244ffd4aa7b865debd036e3751491a33e2415d1e800deb9d4c