Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1aa33ec97a3bb09…

MALICIOUS

PDF

76.3 KB Created: 2021-09-25 10:43:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 552b86d1e4b0d0396084d7864a0a1661 SHA-1: 12e31408e8b4d7e27cd6b0bfb09961d650c645ba SHA-256: a1aa33ec97a3bb09778bb340228a4d50c72309cb5a40f827e3ca203dca3542b2
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple external URIs and link farm heuristics supports the conclusion that this document is intended to lead users to malicious websites. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=otorrents+apk+download PDF link annotation
    • http://tribo.kz/userfiles/File/84156231311.pdfIn PDF document text
    • https://cbdc.co/uploads/ckfinder/userfiles/files/refenikapigudek.pdfIn PDF document text
    • http://buyyoutubesubscribers.com/ci/userfiles/files/72647599961.pdfIn PDF document text
    • https://biomedchita.ru/imeg_master/file/5730991040.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161453379bffb6---29184808271.pdfIn PDF document text
    • http://didongsinhvien.com/upload/files/42165471845.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/062b8d9f9fc66ca7a4f9a7354b5aee94/99811169975.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613484eaded66---dutawixefitezesadot.pdfIn PDF document text
    • https://vibangthuaphatlai.net/uploads/files/42709994875.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/9f79d9a365dd39e99d373dd49ace11d8/17689006434.pdfIn PDF document text
    • https://xn--nmqu14inmf.com/upload/files/28518924686.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145954b8989f---puxozowetuduxemowar.pdfIn PDF document text
    • http://hotstamping.pl/files/file/19923870866.pdfIn PDF document text
    • http://mp-journal.com/media/file/76876307350.pdfIn PDF document text
    • http://jlsxjy.com/right/UploadFile/file///2021091803014173499.pdfIn PDF document text
    • http://7seapharmtech.com/Uploadfiles/files/suxurujer.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16130c82fbacbc---23673591164.pdfIn PDF document text
    • https://kolorubursztynu.kolorubursztynu.pl/web/uploads/files/bawagagevusemorupuwisaw.pdfIn PDF document text
    • http://thegioimercedes.com/upload/files/53128956680.pdfIn PDF document text
    • https://wolfgang-photography.com/userfiles/files/8500977551.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614162b47c109---gisogexolezuxewidu.pdfIn PDF document text
    • http://zamel2.pl/userfiles/file/6284521463.pdfIn PDF document text
    • http://cleangroupbd.com/ck/upload/files/84556446726.pdfIn PDF document text
    • http://residencelesaline.it/userfiles/files/44921991682.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_off0000b9d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9D9 10496 bytes
SHA-256: 55b08309d3979349b7b99197d9b97c904c6cef2691f9fbdda2eda991573e9bce
font_01_sfnt_off0000d1f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1F2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ea04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA04 22128 bytes
SHA-256: 5fa90248b669d0e1c645abbb4d617f2bbcc958f33e7ae90043ab11bbd4ef1351