Malicious PDF — malware analysis report

Static analysis result for SHA-256 e3ddc87562f36d57…

MALICIOUS

PDF

75.6 KB Created: 2021-09-11 06:06:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b1d0386a1bb1d64bec9c19e3fb14c1ba SHA-1: 672654e2cb4a88eb6f445d9503394c7ba3c4b407 SHA-256: e3ddc87562f36d5706e3f39abf83f2232ac26654f42c4236f833d34c15687c31
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics strongly suggest this document is part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • 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 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://chung-pei.com/userfiles/file/21977715484.pdf In PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/161312fe7494c8---sapenap.pdfIn PDF document text
    • https://kattliv.com/kattliv/admin/userfiles/file/36608542623.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/logefoluwowaga.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16137fe31bce97---dojilikejamu.pdfIn PDF document text
    • http://sualpturizm.com/userfiles/file/57802921283.pdfIn PDF document text
    • http://liccuza.ro/stiri_files/file/33501467996.pdfIn PDF document text
    • http://jingkangchem.com/upload/files/vowete.pdfIn PDF document text
    • http://kanchanaspa.com/ckfinder/userfiles/files/30580143029.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/c44ad94cf50971637ed50dc7f6a0a58a/15644380740.pdfIn PDF document text
    • http://swiss-ex.com/images/blog/file/saratigel.pdfIn PDF document text
    • http://newshop.jp/archive/file/wetipipan.pdfIn PDF document text
    • https://fetogram.ir/images/upload/files/kuvedipiwamok.pdfIn PDF document text
    • http://www.masozilina.sk/ckfinder/userfiles/files/likugepedugupulol.pdfIn PDF document text
    • https://es21sys.com/userfiles/file/tewesesonujalodezipumoket.pdfIn PDF document text
    • http://halmar.info/userfiles/file/sudovid.pdfIn PDF document text
    • https://98ing.com/upload/ck/files/20210907_170006.pdfIn PDF document text
    • http://cambridgekapurthala.com/damana/userfiles/file/84593921048.pdfIn PDF document text
    • http://kleinschadenexperte.de/userfiles/file/javadesiwibitujateranom.pdfIn PDF document text
    • http://koala-al.com/d/files/jowozevovafirumibawef.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1613752bee26c4---4793922670.pdfIn PDF document text
    • https://kaplaitalia.it/userfiles/files/21508399055.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=convert+pdf+to+jpg+in+macPDF 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_off0000c37d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC37D 10976 bytes
SHA-256: b40e26a3227865374f06118333c0ce466b61e3d2e61581bb425fb429c46b93ec
font_01_sfnt_off0000dcc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC4 17316 bytes
SHA-256: 8891cd69b74871de6c4eb627e0113de725aae2286293271be15f0a312901acd3
font_02_sfnt_off00010930.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10930 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1