Malicious PDF — malware analysis report

Static analysis result for SHA-256 88d965cb6031e81b…

MALICIOUS

PDF

92.4 KB Created: 2021-08-21 04:44:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2be99020d1301a82fc9cd51bab8be86b SHA-1: 97d55a93e5fccb017541b515f5fb756d5296a14c SHA-256: 88d965cb6031e81bf4be8b019b954aa01000c8ecb1092f36b81b9be402bde14e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous external URLs, many pointing to compromised WordPress upload directories, suggesting a link farm designed to redirect users. The presence of embedded URLs and the nature of the heuristics indicate a phishing or malware distribution attempt, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://synerhu.ru/uplcv?utm_term=how+to+run+channel+auto+scan+on+element+tv+without+remote
    • http://gocchame.vn/app/webroot/img/uploads/files/lomafo.pdf
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/160f020a787414---dikomuzefadagigutibuwe.pdf
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606fb7b79c4ce---kilun.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aab2dbb7e8a---xititizivorojiw.pdf
    • https://sellerflows.com/wp-content/plugins/super-forms/uploads/php/files/1f6c857a87c541e3101dfc751af1752c/lozavowukizasiwu.pdf
    • http://dabbleanddesign.com/clients/c/c6/c60e280709801842a26e47e23f21f170/File/xawekowutaximiwek.pdf
    • http://sdes.in/uploads/mukejek.pdf
    • https://digireg.nz/upload/28505350112.pdf
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160abf5515e967---xuvuvizalukerujawoz.pdf
    • http://tuvanluatdanang.com/upload/ck/files/85858492929.pdf
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbb051609b---xufif.pdf
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160711c416d75b---sefasosovo.pdf
    • http://dermalab.pl/userfiles/file/71750986776.pdf
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/85975389890.pdf
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a9ecda648e7---31022812797.pdf
    • http://dienlanhlongan.com/upload/files/wisevoz.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a1c5043a033---40246023210.pdf
    • https://istruttorecinofilo.it/userfiles/file/5282435700.pdf
    • https://xo-sound.ru/userfiles/file/11730516510.pdf
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/cr2laq33cu2udd953np3unvtt2/62840443323.pdf
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/8312221e4467f9c87063c47a07aa3767/76168821610.pdf
    • http://aire-limpio.com/img/editor/file/lolupesimaletitosar.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e7d7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7D7 16792 bytes
font_01_sfnt_off0000ffe9.bin
13151c8683cf4c686be5dc1d2c8e349323fb5684c57e696c42e6d044ee78b184
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFE9 19000 bytes
font_02_sfnt_off00013044.bin
dbae5d59fe48388d2bf5c5f0dffc09b491a471c71faf4d38a13132b8b3f8f3c2
pdf-font-stream PDF embedded font (sfnt) at offset 0x13044 10740 bytes
font_03_sfnt_off000148c1.bin
40badf1b290cbf856853f394c00d3a0af654cdd39e7a08023b7f861aa89f0f39
pdf-font-stream PDF embedded font (sfnt) at offset 0x148C1 17384 bytes