Malicious PDF — malware analysis report

Static analysis result for SHA-256 57e558f064b14f1b…

MALICIOUS

PDF

70.8 KB Created: 2021-06-13 19:18:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: fdb495fc534a66666c677efd36973fab SHA-1: bbbc5aa8335af73ab177f4b8a70c7c6497a32485 SHA-256: 57e558f064b14f1b937a5877ac8bc6372f676c8d4b6048b72dcd7786d8fd506c
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, indicating it was likely generated programmatically to serve as a lure.

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 https://smidgel.ru/uplcv?utm_term=oxford+phonics+world+teacher+book+pdf PDF link annotation
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a67071f125e---44220357576.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/u5ugriu1trdcsu049lkdjj3r04/10501969178.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/2ug014fln6ae0b0786ru3vksg5/borawolojubaxobokowabosos.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/c94b926f819b5776763bc1105f3c4692/44709210592.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3ccf8112b4---ribuzexagivun.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/30dc15a79a089192545fa79dc02ae015/79662102254.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/1092666fd8ce88fe03cb6b7afcda854f/93532001053.pdfIn PDF document text
    • http://graficaeformazione.it/userfiles/file/tuvifuzezusavej.pdfIn PDF document text
    • http://cnex.cc/images/blog//file/migosavok.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160728092086ec---jazimubugavutu.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc05badfec---90654884553.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0e3d9d3435---46992746824.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/95092590752.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7ad02231d2b3260c12c96930f040a390/dinip.pdfIn PDF document text
    • http://dermalab.pl/userfiles/file/13016228892.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cf67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF67 5632 bytes
SHA-256: 716a8d938e183ebbf198c5d5e9c7a68ec90df01da6b4dc86048492e88503ab74
font_01_sfnt_off0000e29e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE29E 16060 bytes
SHA-256: ad1ed0b3847bf4490f1403e8b8f0abf18eee60f1038bd9bf8106a125baad153d