Malicious PDF — malware analysis report

Static analysis result for SHA-256 91685fb645618c9e…

MALICIOUS

PDF

83.6 KB Created: 2021-09-01 01:02:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 47cd53c6a2677c9825f03dfb4537ad0f SHA-1: 6967288ed8c51e0e8c459365cae2272dbd784ff0 SHA-256: 91685fb645618c9e4826d52c6a3ae694faa29495d99a6c6698cc530a631a0c63
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous external URIs and links to compromised CMS upload storage, suggesting a phishing or malware distribution campaign. The presence of embedded URLs and link farms indicates an attempt to redirect users to malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://infrive.ru/uplcv?utm_term=defending+the+guilty+tv+series PDF link annotation
    • http://jp-cable.com/d/files/28768521496.pdfIn PDF document text
    • http://limoride.net/gallery/file/kajomofikozizazuvifo.pdfIn PDF document text
    • http://enovosti.info/ckfinder/userfiles/files/93020346483.pdfIn PDF document text
    • http://www.yoko-ono.be/images/userfiles/file/19982212712.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/29f9df7633a34b1936710663ccd5a74b/datiloje.pdfIn PDF document text
    • http://bischofs-scheune.de/userfiles/file/ruzafor.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a26e462069---vupowanifojurituv.pdfIn PDF document text
    • http://nissanotogovap.net/uploads/images/files/jezapotatepadu.pdfIn PDF document text
    • https://gyn-koe70.de/obrazky/file/renufizovenuwidedopajit.pdfIn PDF document text
    • https://www.vpn-solutions.com.pe/ckfinder/userfiles/files/jexatagunezoxu.pdfIn PDF document text
    • http://machulski.com/public/file/81468169952.pdfIn PDF document text
    • https://etonbio.com/newsLetters/images/file/71700801314.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/d5e4dd39eb16236b27d76189e0ea6e59/novawudiroge.pdfIn PDF document text
    • https://ferado.vn/userfiles/file/degugi.pdfIn PDF document text
    • https://tonwen.org/userfiles/file/52835948333.pdfIn PDF document text
    • http://akinmedikal.com/uploads/file/pevow.pdfIn PDF document text
    • http://the100voicesofgospel.de/fichiers/newsletter/file/57134805744.pdfIn PDF document text
    • http://energo-winstal.pl/userfiles/file/661465323.pdfIn PDF document text
    • http://onmamtour.com/FileData/ckfinder/files/20210814_57F8639B32CB73F8.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160bbe22cacaba---89238928608.pdfIn PDF document text
    • https://digireg.it/upload/16324450491.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/16117f4fa543f0---94804148575.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_off0000e13b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE13B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f94d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF94D 18308 bytes
SHA-256: b86a7fc535f4e18c98dc1418724e355438fddfcae974c299f35ee73ebf31216b
font_02_sfnt_off000128d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128D6 10632 bytes
SHA-256: 0332c48ed6ebd4bbe690938fc27390f9f88e0ba6cc154317ccd4464df92e55f1