Malicious PDF — malware analysis report

Static analysis result for SHA-256 dd1691d4fa64b70e…

MALICIOUS

PDF

72.1 KB Created: 2021-04-28 13:07:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 63472d3da22dd3e4cee26ca27dbc6aa0 SHA-1: 4f7c6cf187cc35588f79a9727fb25a66fd84c3d6 SHA-256: dd1691d4fa64b70ef23aca8246f00411dddf64798627d3c20175adb840cef40b
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm, pointing to multiple compromised websites, likely to disguise malicious downloads. The embedded URLs and the PDF structure suggest an attempt to trick users into downloading further malicious content, possibly related to 'schoology app apk'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://beaumont-residence.com/wp-content/plugins/super-forms/uploads/php/files/bkb73i637ujpc1m5v9770shjkv/18491469825.pdf In PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/160774abc67076---5916701351.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607ccf62a3fe1---64553281732.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/4bnpr9500vgm8553ldmju8gadr/fuworilupukafepugirato.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd27485393---6090214597.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16076e4b7ae209---79613063468.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/3affd7c56ba94c4ef44ead5a5fc706e8/zewatudefojupazomaru.pdfIn PDF document text
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/a1083080ec2a951314bef9a3c0d07243/xuvibona.pdfIn PDF document text
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/1ea7221859284fc0e82fa95b5bf3ca13/jitimadinonijorilogililif.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f360df18b9---50158423648.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/a132a8e059e73ba18cc3690ed9e0bea9/5708766933.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/24294482999.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/a33829e794e2b747a58e4721900c9648/vaterusededejimur.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/~3/3CAf4wW3hvY/uplcv?utm_term=schoology+app+apkPDF 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_off0000de22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE22 5192 bytes
SHA-256: 5b9e3bafbee32630a4675529b799c289604763a57501994921cfd08afd71e96b
font_01_sfnt_off0000efdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFDD 10628 bytes
SHA-256: f0c76df102611dc843230168e80c28fa887e708192a11a358177ae823b41dae9