Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f26d27a7d0a51a8…

MALICIOUS

PDF

80.3 KB Created: 2021-09-12 03:11:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 82849e9c6352ed4ad12ac2cbeef44d20 SHA-1: d833202a474eac410aa6500875ddc04d0139ab38 SHA-256: 4f26d27a7d0a51a8156093fb33e5852af43bd7d07c03e9edcd7bcd8596412ded
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to compromised WordPress upload storage and other disposable hosting sites, likely to facilitate malicious downloads. The presence of embedded URLs and the nature of the heuristics strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://cestovni-postylka.eu/userfiles/file/39830185445.pdf In PDF document text
    • https://derfo.info/resimler/files/47005946027.pdfIn PDF document text
    • https://majubesar.net/contents/files/wimowezalefubama.pdfIn PDF document text
    • http://mislenyiallatorvos.hu/userfiles/file/90771960814.pdfIn PDF document text
    • http://gocep.org/data/userfiles/files/89936278481.pdfIn PDF document text
    • https://maintogelonline.info/contents/files/71685554959.pdfIn PDF document text
    • https://duhocblueocean.vn/ckfinder/userfiles/files/luxobepivawaz.pdfIn PDF document text
    • http://cleanking.net/userData/board/file/mevodukubeputudodonatepe.pdfIn PDF document text
    • https://illinoisfiscalpolicycouncil.org/app/webroot/userfiles/file/roxidodaxeriratulorusovo.pdfIn PDF document text
    • https://pixel.bg/img/file/sunetujov.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/cf8e0c2bqo19dg0fv14jb75aq2/62965960126.pdfIn PDF document text
    • http://jl-vacuum.com/upload/files/ziledizowujev.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/82585914195.pdfIn PDF document text
    • http://elencostruzioni.it/userfiles/files/88485797298.pdfIn PDF document text
    • https://hiperaktivite.info/userfiles/files/99130177185.pdfIn PDF document text
    • http://veterinariacasettamattei.it/userfiles/files/doduvuzurademuviriki.pdfIn PDF document text
    • http://kubablimel.pl/Image/files/44959077850.pdfIn PDF document text
    • http://pescepiana.eu/userfiles/files/55963562920.pdfIn PDF document text
    • https://commonlawhouse.in/userfiles/file/luvagisisu.pdfIn PDF document text
    • http://sitoad.com/bbqjoekey/files/202109062203159023.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132ac565ff64---gedisufodovev.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16136967d3c993---fomikukabaxeper.pdfIn PDF document text
    • http://mea-travel.pl/userfiles/file/46016809722.pdfIn PDF document text
    • http://dunakeszi.varosom.hu/userfiles/files/89988403007.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=download+gta+5+android+no+verifyPDF 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_off0000d141.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD141 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e958.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE958 10764 bytes
SHA-256: b663c0cfe53cb05042c6b3e9a1a35b8943895604dde4c1c384a066b258c79f9f
font_02_sfnt_off0001021c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1021C 18648 bytes
SHA-256: e61e320582edc66b3b0f231ef111ca71ce1e3283574f7e7b03f3a59ee20f5ecb