Malicious PDF — malware analysis report

Static analysis result for SHA-256 783e654f192571f3…

MALICIOUS

PDF

87.7 KB Created: 2021-07-13 17:55:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: d9691f2a593dc709b85a78d42fb68a35 SHA-1: 8f5e2c9135de729a443ac63554c9e9adbd8e1449 SHA-256: 783e654f192571f302916c1164c0fba043c82d85734d030a18d1c9c6c8392076
96 Risk Score

Malware Insights

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

The PDF file contains a large number of links pointing to compromised WordPress sites, indicating it functions as a link farm. The ML classifier strongly flagged this PDF as malicious, and the embedded URLs suggest a phishing or malware distribution scheme. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool rather than user-readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 5

  • 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://smidgel.ru/uplcv?utm_term=what+color+does+cyan+and+blue+make PDF link annotation
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/50e8a0a636856be8cbdd6f5aac658976/7312068095.pdfIn PDF document text
    • http://bong-dem-long.org/upload/editor/files/lukeruzavolev.pdfIn PDF document text
    • https://actorconseil.com/files/file/15572006705.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/9575445087.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/160adba72a20e2---wiwenaloguriwekuxufesoto.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/wubokezazujopekubijef.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/ndr3tlukjhpcihtfs3qcjpdu3t/43808855429.pdfIn PDF document text
    • http://varanini.pl/userfiles/file/50665443969.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f4bcfa03d9---wupurifakezasuga.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/49lku2jdc4a4637qulf28mvm04/fufiloxavobusiw.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/2e1ceb39b98b1c596ed95fc3e8586030/xonivegalile.pdfIn PDF document text
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/arfv6aaitldjpn45sso16707pb/lubukonixol.pdfIn PDF document text
    • https://medicentrumnz.eu/medicentrum/files/file/wazet.pdfIn PDF document text
    • https://baoyi-chuck.com/ckfinder/userfiles/files/95804967176.pdfIn PDF document text
    • http://aldo-ins.com/userfiles/file/dowoxikutizokevopamunesis.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/c2510ef2c9b2dc35b2752940490a2e72/5062486593.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608e483b33803---3814781424.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8ffc83511f---3516594007.pdfIn PDF document text
    • https://bursac.net/userfiles/file/30895603186.pdfIn PDF document text
    • https://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/1obkll6b2he76o5ohv45h58gn1/noxew.pdfIn PDF document text
    • https://charlesstreetvideo.com/userfiles/file/nuramopuxojivija.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/23bbdafffbe6d6e274e7ca6735081eb6/99580660931.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/65322117743.pdfIn PDF document text
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/amlgnd91096s9iq938rj6pf223/lawasetowunozuribavati.pdfIn PDF document text
    • https://mimpishiosatu.com/contents//files/19152177606.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/ppgfntcqr8vecm67l0vo6u617l/21270349728.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_off0000ee89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE89 10980 bytes
SHA-256: 382b7d5e8e1dcad2ce7200ad6f4951b1d92bfd1e1c999b404f6cce48232f6fdd
font_01_sfnt_off000107f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107F3 19516 bytes
SHA-256: 02ef659b767fd2cf5da0001b18fe6af435487df9c31dbf299e65e3eb9adc03d9
font_02_sfnt_off00013951.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13951 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1