Malicious PDF — malware analysis report

Static analysis result for SHA-256 143efdf6a982763e…

MALICIOUS

PDF

73.3 KB Created: 2021-09-17 06:20:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: dd0ae7b0de4ecfddb17b325659531e0b SHA-1: cfce2291e84cd19d373435cbe835cdb50c14df6f SHA-256: 143efdf6a982763e67e2d58d4a595d8f2e2d06710d2b8b4ca2328a3be2896e53
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links pointing to external resources, many of which are hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://medvor.ru/uplcv?utm_term=download+torrent+apk+for+android PDF link annotation
    • http://montoaneli.com/ckfinder/files/vepezabujorewavona.pdfIn PDF document text
    • http://sbsedupatti.com/sbsedupatti/userfiles/file/jilefirug.pdfIn PDF document text
    • https://gertiesbloomers.com/kousumi/nulook/upload/fckimages/file/88119339632.pdfIn PDF document text
    • http://www.juthamasclinic.com/upload/finder/files/22564387975.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16136034d8999e---18855570103.pdfIn PDF document text
    • https://projetounificado.com/uploads/files/19916805934.pdfIn PDF document text
    • http://freestyler.cz/img/file/79472503736.pdfIn PDF document text
    • http://ediliziaunoaventi.com/userfiles/files/walitebubimotakijavugosa.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/keroj.pdfIn PDF document text
    • http://mwbright.com/upload_fck/file/2021-9-7/20210907130938500231.pdfIn PDF document text
    • http://spy-military-labs.com/userfiles/file/28831540817.pdfIn PDF document text
    • http://jfac.kr/ckfinder/userfiles/files/44039873914.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/vblrl01nns68g5sbsotncgvntc/19104611410.pdfIn PDF document text
    • http://pilanatofishing.com/home/sandbox/domains/shelter.sandbox.tritek.hk/public_html/ckfinder/userfiles/files/15182750975.pdfIn PDF document text
    • http://lucidareemantenerepavimentifaidate.it/userfiles/files/93295149362.pdfIn PDF document text
    • http://homeshopeez.com/uploaded_files/userfiles/files/83371403050.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/9o59mkuqere2lmeh4mdbmcb7a2/23078396825.pdfIn PDF document text
    • http://chulatutoracademy.com/chulatutor/ckfinder/userfiles/files/90903854388.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16130033c17437---mosokowenilifewutilisa.pdfIn PDF document text
    • http://stellarp.com/userfiles/files/39706909630.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/91407538547.pdfIn PDF document text
    • http://alisawedding.com/upload/users/files/80433573000.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_off0000bbf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBF2 16936 bytes
SHA-256: b79e5a95b4467b775505d683d410d1d4b0dbaca64aa59b2263e96c4e56f987d3
font_01_sfnt_off0000e78e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE78E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ffa5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFA5 10504 bytes
SHA-256: 98e8d67fa3a6942f353478161499c63ed27dfb049bf00d7d07d5bae7a8dd90c9