Malicious PDF — malware analysis report

Static analysis result for SHA-256 957a3551cf4ba3d4…

MALICIOUS

PDF

73.1 KB Created: 2021-09-25 23:00:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: d134829bbdbeeffb24802f50bbedcd6e SHA-1: 33621a2305f62cab5280c0458a869ad685f15e42 SHA-256: 957a3551cf4ba3d468eeb423de6afb72cc7a0d65ea72c4a6e52a4e8f2aa1cd29
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, directing users to numerous disposable hosting sites. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the link farm heuristic point towards a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://fw-simple.com/uploads/files/7123483258.pdf In PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/1d813iqvubdp2p4gcdde1k4vc1/64614596978.pdfIn PDF document text
    • http://theponghop.com/upload/files/tajemuvusipigujoxel.pdfIn PDF document text
    • https://hotelite.in/userfiles/file/mexipexevonawuwoxosi.pdfIn PDF document text
    • http://radiopoint.cz/userfiles/file/kuniziwifebutuger.pdfIn PDF document text
    • http://www.photonics-science.com/ckfinder/userfiles/files/bisamezapokapuxolemu.pdfIn PDF document text
    • http://yucehukuk.com/resimler/files/78333897699.pdfIn PDF document text
    • http://tootingtaxi.com/survey/userfiles/files/38094980284.pdfIn PDF document text
    • http://sportsgarten.com/editorData/file/46226771207.pdfIn PDF document text
    • http://rdasesores.gestconcursal.com/editor/ckfinder/userfiles/files/57098948816.pdfIn PDF document text
    • https://hophamthaibinh.com/upload/files/filububivuguxopuliga.pdfIn PDF document text
    • http://www.bash.cl/media/file/65968844741.pdfIn PDF document text
    • http://77owship.netsociality.com/upload/files/josabozin.pdfIn PDF document text
    • https://pactforfamilies.org/ckfinder/userfiles/files/zanusamepoxa.pdfIn PDF document text
    • http://eaupureinternational.com/userfiles/file/44658659850.pdfIn PDF document text
    • https://semot.com/Store/userfiles/file/61099280296.pdfIn PDF document text
    • http://www.truca-taoules.com/ckfinder/userfiles/files/15213960681.pdfIn PDF document text
    • http://klhl.com/userfiles/file/48241223150.pdfIn PDF document text
    • https://intrigantka.ru/images/userfiles/file/nejiriribokupovo.pdfIn PDF document text
    • https://www.adoz.cz/ckfinder/userfiles/files/punigatujemudofomimijakib.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/jukevirigazisivolute.pdfIn PDF document text
    • https://anukulagrotech.com/ci/userfiles/files/57705596437.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/suvelajuzubuzelumusemuv.pdfIn PDF document text
    • https://eurosan.pl/user_images/file/paxopagejidutekawodijo.pdfIn PDF document text
    • http://solar-makernavi.com/ckfinder/userfiles/files/63028552653.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=ultimate+car+simulator+mod+apkPDF 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_off0000b796.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB796 17920 bytes
SHA-256: a427626683f010d43fc4940bd5ca928b5846ba21aed8d838b297528b85a59aa1
font_01_sfnt_off0000e5bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5BB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fdd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDD2 10768 bytes
SHA-256: afdfc5205b3005a6f450784b0943c48abf6d4b51aff37a6eca89e40a9bc305d7