Malicious PDF — malware analysis report

Static analysis result for SHA-256 4277b1c650d9a52d…

MALICIOUS

PDF

86.5 KB Created: 2021-07-03 08:06:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 09a53601650c6806cbf2ef6cac2bf155 SHA-1: 3e96d2861d6dc3cd0b5d9b5aa00cfa37813604eb SHA-256: 4277b1c650d9a52d6007d8d930d487e5f5da70c6f3d5178cfbd4d25bfafa0a04
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It functions as a link farm, directing users to numerous external URLs, many hosted on compromised websites or disposable domains. The presence of embedded URLs and the overall structure suggest an attempt to distribute phishing content or further malware payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://coretry.ru/uplcv?utm_term=how+to+create+a+dataframe+from+vectors+in+r
    • https://speculatio.in/ci/userfiles/files/wofulojumaxagijujaza.pdf
    • https://pablohernandes.com/wp-content/plugins/super-forms/uploads/php/files/bc32e79409c5a4123c02906a82c8415d/funifibazujanepone.pdf
    • https://schmitz.cz/res/file/72906457242.pdf
    • http://detikakdeti.ru/img/file/44999090161.pdf
    • http://russkiivopros.com/images/FCKeditor/file/fexofoxuzaw.pdf
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1609a61f4807ee---76039899362.pdf
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ede5ad052c---78268068726.pdf
    • http://jjmcp.jp/userfiles/Image/file/sonebiwuv.pdf
    • http://mayamalay.com/clients/874202/File/2557274228.pdf
    • http://residencecarlofelice.com/userfiles/files/46387130925.pdf
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/18f20658d72b04cfa948da0bdb790516/33077719643.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fcfa311764---bajufaxogugopifigidarax.pdf
    • https://panama4d.com/contents//files/22087234012.pdf
    • http://xn----8sbxab3abskk3a2j.xn--p1ai/media/file/29549212453.pdf
    • https://workinhotel.com/upload/fckfile/557830315.pdf
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca4e3941b7---87832794113.pdf
    • https://kimtuong.vn/isc/public/files/fckupload/file/3394484092.pdf
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/dcbe3dac8339ae3f14e63b9e9ceed3d9/60724905835.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160790a2758c3e---laxenipomutidujope.pdf
    • http://vorne-sitzen.eu/pcms/content/file/46899689374.pdf
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/160768f1334af2---46837689835.pdf
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c76acf1d668---nawat.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9f8bdac242---sowixigaboju.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_off0000ebbf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBBF 16792 bytes
font_01_sfnt_off000103d6.bin
a2395d30b8f7e5179050f9cec9e8c269cdcced5b23183e0d64a0393c2d9f005b
pdf-font-stream PDF embedded font (sfnt) at offset 0x103D6 10732 bytes
font_02_sfnt_off00011c84.bin
befde66f0a33d1e18632da66921db34de68285190b246ad2af2afca45bd8deae
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C84 17508 bytes