Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f868244b035fa98…

MALICIOUS

PDF

92.9 KB Created: 2021-09-22 13:22:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: c044f268053182e35e7024bb2adcdcad SHA-1: 9d24d53523a5e736dc2f4b8e75430f3d61e5a9cb SHA-256: 5f868244b035fa983b0b0ba8247c31d356a248e14aaed79bd552f9ff8b35eebd
134 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV, specifically as 'Pdf.Phishing.Trojan'. Static analysis revealed embedded JavaScript and a significant number of external URLs, many of which are hosted on potentially compromised or disposable domains, forming a link farm. This suggests the PDF is designed to lure users to malicious sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.4046

Heuristics 7

  • 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 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 http://perles-del-beya.com/userfiles/file/moviba.pdf In PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16137e63b0a531---wimanozo.pdfIn PDF document text
    • https://mycocoa.org/images/upload/files/wuluranidil.pdfIn PDF document text
    • http://lagrupacio.cat/file/gezofepubedigapox.pdfIn PDF document text
    • https://readandenjoy.ae/userfiles/files/valiwum.pdfIn PDF document text
    • https://muratay.nl/userfiles/file/41599859156.pdfIn PDF document text
    • https://matao.ro/app/webroot/files/userfiles/files/11965415371.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/loledatawepumanok.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/muripisez.pdfIn PDF document text
    • http://starcity-vinhomes.vn/app/webroot/img/files/43340931569.pdfIn PDF document text
    • http://hongsung114.com/files/fckeditor/file/15739924807.pdfIn PDF document text
    • https://onutglen.com/caningest/images/file/dizezaxefufi.pdfIn PDF document text
    • http://mega-gold.com/userfiles/files/2936127880.pdfIn PDF document text
    • http://secretsocietygroup.com/temp/vinney/HTML/userfiles/file/86880318130.pdfIn PDF document text
    • http://tamker.hu/userfiles/file/1297794733.pdfIn PDF document text
    • http://methese.com/upload/files/zorejozeluvugebex.pdfIn PDF document text
    • https://gtijsr.com/userfiles/file/40677320374.pdfIn PDF document text
    • http://tridiart.cl/ckfinder/userfiles/files/lidaxudujad.pdfIn PDF document text
    • https://lorus.rs/files/89137402264.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f89152c837---50531692559.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/5545979eff8dd1ed51d1627c515f2530/40715162077.pdfIn PDF document text
    • http://cautrucpalang.vn/webroot/img/files/89704210837.pdfIn PDF document text
    • http://paintmaster.hu/js/ckfinder/userfiles/files/93769327926.pdfIn PDF document text
    • http://newgrids.com/userfiles/file/mosikokuwajolazogis.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/84551510698.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=hulchul+old+moviePDF link annotation
    • 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_off000112e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112E0 17228 bytes
SHA-256: ad7f0366fd0a115b0fda173e4501c9d11ceb598aebcda40679a93cd6d3870c28
font_01_sfnt_off00013f85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F85 10160 bytes
SHA-256: 050efc6378dee6482ea98929f68cb928aec34c480c1946d9db0a315778101662
font_02_sfnt_off0001562c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1562C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1