Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcb9d6f4abf30536…

MALICIOUS

PDF

81.9 KB Created: 2021-08-26 09:11:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 1127299f4d21e97413ffabfa634d552c SHA-1: 50f090f303111fbacc992eeb545891913bdc74f1 SHA-256: bcb9d6f4abf3053616a6a3ddb656b4c8b69f8b771750c2d8092fa65617818e93
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to manipulate search results or host malicious content. ClamAV detected this as Pdf.Phishing.Trojan, and ML classification strongly suggests malicious intent. The primary attack pattern involves luring users to external sites through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://cructi.ru/uplcv?utm_term=html+link+text+decoration PDF link annotation
    • http://poddertradingandindustries.com/userfiles/file/nijezimasiwagutizojimud.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/xokomulalori.pdfIn PDF document text
    • https://emmaushuis.org/pages/pimulegasozutilawamotisum.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/89333884976.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c85a938fdaa---51110582658.pdfIn PDF document text
    • https://zhansq.cn/upload/file/21723001405.pdfIn PDF document text
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/jijefogajulefupeji.pdfIn PDF document text
    • http://st-ark.it/userfiles/files/jewugokibusijowu.pdfIn PDF document text
    • https://knurussian.kr/DATA/upload/files/202108160248032862.pdfIn PDF document text
    • http://kaupa.cz/userfiles/file/9167815055.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160bb6d3445ce7---39671659534.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/05f0cb22272f310eddd0ebf5cfdf86cc/16119573444.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/84445640392.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/huu4qpkp9bho02agb8jr0stgi2/13905169940.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608781af54289---10421316964.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/f656d645e2b962b947528e4bdbfa05e8/33575895774.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/q2oop6t8qglc8lnfg40s69a2rl/31406968830.pdfIn PDF document text
    • https://khotelmarket.com/FileData/ckfinder/files/20210629_16E7D4C7FCB20726.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/59626458718.pdfIn PDF document text
    • https://luatsuavina.com/userfiles/file/nezonemotip.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/061545255094.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16121785a192e3---gedizubojawevugikip.pdfIn 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://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_off0000dbc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC9 10548 bytes
SHA-256: 404b91356ef668599bb2d83703417fc1c88a9e5bc2b110e31ccd66b5bf3c3f14
font_01_sfnt_off0000f3b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B2 17864 bytes
SHA-256: 1bac8e950c44c2e49ff2a2dffd2d3971119f98f261a15304755631df76b8e5b0
font_02_sfnt_off0001226c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1226C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1