Malicious PDF — malware analysis report

Static analysis result for SHA-256 51d6c4d61338b2f8…

MALICIOUS

PDF

94.2 KB Created: 2021-09-04 18:07:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a39bea7aca643a58d78176312358f3ed SHA-1: 66d433534da25d4f86492a191afe8cdca9bf86c2 SHA-256: 51d6c4d61338b2f8cc8d91f44e5a7cc5666a990e4cb4df6582d2d14960691b95
156 Risk Score

Malware Insights

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

This PDF was flagged by ML classifiers and ClamAV as malicious, indicating it likely contains an exploit. The heuristics reveal it functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting. These links are likely intended to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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 http://ourconn.com/userfiles/file/202108161034413532.pdf
    • http://younewstoday.com/task/userimages/file/pegojotewivaz.pdf
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/733e81f1a38375773029075d47e9f92d/mafurepafevezabesowopew.pdf
    • https://vonia.mikludava.lt/images/files/wumuwigu.pdf
    • http://buren-kompanie.de/userfiles/files/bupajamemotoje.pdf
    • http://sushi-belovo.ru/files/58243429498.pdf
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a9ba2a88ef2---lituri.pdf
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/b2f6d889524dca93263ad3c767be1081/31402546246.pdf
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/e7da1335fe6b0f279f73c516254b3776/64093042766.pdf
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608d0480bd613---dekinikirodutojexejonudar.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/27ed92548a7229012796d7a3b8aab759/mejiwosimamebotitowopow.pdf
    • http://bowlingkillers.com/imgdb/files/wolufowe.pdf
    • http://nineslash.com/user_file/file/nipinut.pdf
    • https://deltarealestate-eg.com/userfiles/file/dekenojin.pdf
    • https://virker-ikke.dk/files/padifapimivo.pdf
    • http://heatherjansch.com/ckfinder/userfiles/files/luvuponovibakozenijomusa.pdf
    • https://vidolamerica.org/wp-content/plugins/super-forms/uploads/php/files/ca19114369e5359c0e446a529afad619/84547116940.pdf
    • https://kangaroovietuc.vn/webroot/img/files/60985432436.pdf
    • https://hoatuoi360.vn/uploads/files/musuxagimuzupiwogag.pdf
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/2gf6c1icf3ibvso2io2o5fl661/lobodotoxewirekel.pdf
    • https://gbagencement.fr/uploads/file/48009663157.pdf
    • http://hhoasis.org/app/webroot/img/fck/file/11480279695.pdf
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e21de448f0e---nosekon.pdf
    • http://splogservice.ru/content/file/67091043557.pdf
    • https://musikkursus.dk/userfiles/file/73282743424.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=list+of+common+verbs+in+spanish+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_off00010647.bin
e25c1c5c7b6eb3993dce2a820588cd3eadf92a6c1d0965e5b2c6d29df452112b
pdf-font-stream PDF embedded font (sfnt) at offset 0x10647 19912 bytes
font_01_sfnt_off00013a02.bin
8a48d87b875103832051ae19c4b2c0f5de6a1028749908d5a13a2b9377b9e476
pdf-font-stream PDF embedded font (sfnt) at offset 0x13A02 11000 bytes
font_02_sfnt_off00015332.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15332 16792 bytes