Malicious PDF — malware analysis report

Static analysis result for SHA-256 4366716a68fd4414…

MALICIOUS

PDF

72.6 KB Created: 2021-06-24 00:50:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: ceeab72fcb0c8503830bb083ec836fcf SHA-1: 72a4bb56bf5cdf260434f6cc08096c9edc3d06f5 SHA-256: 4366716a68fd44144be27526e9e569091d34dfb135af90c13f7e8899192ccf00
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting it's used to distribute further malicious content. The document body, though heavily obfuscated, contains text related to 'PCA competency test answers', which is likely a lure to encourage users to click the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607312fc19c0c---vuxefadowazikajatumaxipul.pdf In PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf80982f83---xupamigogaganupaluzomow.pdfIn PDF document text
    • http://tano-cable.com/d/files/bipodipigudodumurepi.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16085e926e2ea0---vebixijorupexativ.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081a8accb2b9---karepataviwokup.pdfIn PDF document text
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/jruk2nb0u17a88r4huts9lu2c8/ravesetobukor.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/uf16765b8pka1hmsah8fjsoldk/76940072177.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/f1abeee687fcd232dd989dcbaadc6b92/33559619141.pdfIn PDF document text
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/46ad84b180e73b392f408f4f250a8daa/polixugamozajaguwagula.pdfIn PDF document text
    • http://xn--e42bt3l.net/upfile/files/23036353498.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/oqfkujk8u4tbss3blg81n88ee4/puvokesoterifijalo.pdfIn PDF document text
    • http://unseenadventure.com/userfiles/file/zorenujufazosar.pdfIn PDF document text
    • http://kondicionery-dolgoprudny.ru/upload_picture/file/5309614484.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160810f382047a---lekonejidapopivabomavogo.pdfIn PDF document text
    • http://soldresold.com/Shradhdha-Mehra/soldresold/final/ckeditorimage/files/xabeze.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/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=pca+competency+test+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_off0000dd8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD8D 5244 bytes
SHA-256: d01f1c4c08b1897382e98c472c768e27a3a3efdd668bd0b219f2eef91f3b6028
font_01_sfnt_off0000ef62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF62 11204 bytes
SHA-256: 05b96f5ffeeddfc5706a05602a0f7affa398caf4b4fbc97ec9ac3b049ca8c538