Malicious PDF — malware analysis report

Static analysis result for SHA-256 edb26b7b775ef591…

MALICIOUS

PDF

71.6 KB Created: 2021-06-23 01:25:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 571d343bb6c871ca0e4f97bf7b63a76a SHA-1: d33cf3e1369d468117db24743981279ebf26e2a8 SHA-256: edb26b7b775ef5912c7953ed167b45777969db7fb0a6242b7644804e31486c10
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload directories and disposable hosting, suggesting a link farm designed to redirect users. The document body, though heavily obfuscated, appears to be a lure related to 'chemical compounds ionic and covalent bonds worksheet answers', aiming to trick users into clicking the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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.
  • 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://skolicka.eu/foto/images/file/54153090915.pdf In PDF document text
    • http://school19-zav.ru/userfiles/file/ziwusosabafizifun.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/16082974425084---8182277606.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4105f8cfb5---matozomibumofiwo.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/togamimumivi.pdfIn PDF document text
    • http://tienhasteel.com/app/webroot/upload/files/tumur.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/9491bbfa5b67a16aeed1b9c68125a56c/62179031920.pdfIn PDF document text
    • https://al-farh-iq.com/upload/userfiles/file/digovixonokoxupefafazava.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/78312338380.pdfIn PDF document text
    • http://amexeuro.com/an3_Uploads/file/jusulolemowej.pdfIn PDF document text
    • https://ikima.fr/uploads/file/sedax.pdfIn PDF document text
    • http://bradleyhillsapartments.com/demo/uploads/contents/file/jarotomavuporojutomefaje.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2b918edf2e---wutofu.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce76d95310---tixefozikusiwedomit.pdfIn PDF document text
    • https://balajitutorial.com/admin/userfiles/file/tukisutenabarenogopaze.pdfIn PDF document text
    • http://www.cerathai.com/image/upload/File/semegojuju.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/760ef16824d0e493108cd25b9a5e2d93/tomuwafubevapamozo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=chemical+compounds+ionic+and+covalent+bonds+worksheet+answersPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA60 5576 bytes
SHA-256: da50b8911cb13a92ae6050e518c4b235981806b1cf47d8701aff7562ca6983cc
font_01_sfnt_off0000ed2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED2B 10616 bytes
SHA-256: 68f375808724e25e04462df35af82e9f8db6171cf2bee59c806abba7b4a06384