Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4cef8268fbc258e…

MALICIOUS

PDF

89.2 KB Created: 2021-07-03 14:55:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3188d9a5efb59b66c196ba7f70d75c77 SHA-1: 75e228b73c8e3ce5c481391a4bdd8ff4939dce62 SHA-256: a4cef8268fbc258eb8c45a3283ba9f073840e8c5cb7b74a6587c438583df3786
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous URLs pointing to various domains, many of which appear to be compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the overall structure indicate an attempt to distribute malware or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://queure.ru/uplcv?utm_term=harry+potter+and+the+sorcerer%27s+stone+full+online
    • https://taechoclub.com/FileData/ckfinder/files/20210624_CD9872959C6CDF5C.pdf
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160922c6a02236---73893125079.pdf
    • https://capitalsyndic.com/userfiles/file/xakupobox.pdf
    • http://zpb-maciejewski.pl/upload/fck/file/xijatibom.pdf
    • http://hockeydh.com/files/ups/files/6638054760.pdf
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/acf5b2ed09a0e7c93c1884d36f6e2973/zabifajemegari.pdf
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609fa5e9f2bde---77614978016.pdf
    • http://xn--80aafbkbafwdti1ahihccrg.xn--p1ai/pict/file/24710524195.pdf
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/odeq55eg2g6hakfnt7msk63a0j/8751445758.pdf
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/441dfc72cfde3922db0c9ba1a11732a5/74575860071.pdf
    • http://aftckwt.com/uploads/file/23461111896.pdf
    • http://szzxwx.com/Upload/Upload/file/20215291427179415.pdf
    • http://neboskreb-irk.ru/uploads/userfiles/files/25990455565.pdf
    • http://ahxxzx.com/userfiles/202106/file/pekokebopatosasigaromiz.pdf
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/n9mbtirmsag63obcc51rodjbrd/45128217170.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5de03af206---25097129322.pdf
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/dt6dph1eanakktjihvmlpofj62/feluwivewuj.pdf
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/3c713c4ddb369811264f5b7c67bf0a96/95483941530.pdf
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609658df24621---revujop.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606da1ce8d181---99730604471.pdf
    • http://damoorefamilyreunion.com/clients/7/71/71c8bb141a0941b69292984b9770a174/File/46730675722.pdf
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/1fefb6a165f159f31bcc18f190398194/perobilonatiboguzigix.pdf
    • http://euro-ex.com/images/blog//file/xagozijawozasez.pdf
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16089fc5085e33---48273674755.pdf
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/ip7fsme7mt0fd3k02appi1i3dv/47143999722.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607aae99ce9da---dokuvusojarorexel.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f7f0.bin
3eb65ca08a533372b44824f79369cc2397ae1c5420d1908c6c8f6925dd2adafd
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F0 17376 bytes
font_01_sfnt_off00012552.bin
9a702bc96a5bf8bdae1b5fa3658edda6dcb3c590500ac5ae31656c567f960d14
pdf-font-stream PDF embedded font (sfnt) at offset 0x12552 10956 bytes
font_02_sfnt_off00013ead.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13EAD 16792 bytes