Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c55e528bb74957b…

MALICIOUS

PDF

88.5 KB Created: 2021-06-26 22:41:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: f1ee9bca5420b5d94248aae47f24c751 SHA-1: 275a8a522efd5bab29082c830f1dbe6b62b332fa SHA-256: 3c55e528bb74957b387b0a333f2f604b9637c22990a58d9f8f69f11e6c86ff25
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was detected as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to potentially compromised WordPress upload directories and disposable hosting. The PDF structure itself is minimal, suggesting its primary purpose is to host these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://airconbank.com/upload/fckeditor/file/vowaxupepitigaru.pdf In PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/0lvcouj0r3bg1g9po46pmc3qr3/fawipatotibofuvakago.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16078c363d6b69---36985117917.pdfIn PDF document text
    • http://podiummoda.ru/userfiles/file/fakuvaxepor.pdfIn PDF document text
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/39450f45c0a11fc648424a68e6e97bb4/66475886477.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f2cf96fcf4---fujimapuleditile.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/dufoxoxonuragowuvusi.pdfIn PDF document text
    • https://salubrismd.com/wp-content/plugins/super-forms/uploads/php/files/d732be8438f3ae7b1e4ed8d9ae76d195/93270105242.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/b63e719274953f4586e02e85f7415a61/zasan.pdfIn PDF document text
    • https://luminex.pl/upload/file/75483946549.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/kapejekugarinosefar.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/difavisaminuvowoporeguzi.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bdfa8a9181e---kijiderubaxuraletuz.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/50590395081.pdfIn PDF document text
    • http://meyanko.com/userfiles/file///sarepixajatovo.pdfIn PDF document text
    • https://plasy.com/uploads/file/vuxud.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087941758eb3---96417764594.pdfIn PDF document text
    • http://wchs65.org/clients/b/bb/bb65574a37642f7fe3135935df861e67/File/47118006063.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbfb33faf7---rulafe.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c3c2efc7ee2---xapajekixipek.pdfIn PDF document text
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/ac5cf350a1ed3e100be81fe570c5b5f9/71253093471.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16080614aefa85---68197399376.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075889cdf480---jolazelezezefofisenu.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/75935344399.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/160afa9aa2eb59---dusozakedenutas.pdfIn PDF document text
    • https://thefertilizerequipment.com/d/files/timudakilevukudi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=may+allah+protect+our+marriagePDF 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://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_off0000f7f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F9 10756 bytes
SHA-256: 5b5fc8fbf639d6ff1727254199a2a851ce5b0c18e61383ec944df4466b437952
font_01_sfnt_off000110c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000128d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128D5 16968 bytes
SHA-256: 6262c484ac6e8492cd1eb3df0d72ea10277bbfce5667ce265be3048d4c5d3edf