Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef5b59a9328c572d…

MALICIOUS

PDF

79.9 KB Created: 2021-09-12 10:15:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1a7e908159c5e85e1c8b77347c162339 SHA-1: a57bce86ff0a31ee6856ad02bf5079bbf925feee SHA-256: ef5b59a9328c572d630fe8321bd462b4d71cf58b61ff1e6162a45f733eccd373
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to distribute malicious files. The ClamAV detection and ML classifier strongly indicate malicious intent, likely 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 0.9960

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 http://hotelalbicia.com/userfiles/file/54868918992.pdf
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16133a85299aa3---begivetiguxiwosevo.pdf
    • http://goldendoodlesofthesierranevadas.com/userfiles/file/30427873935.pdf
    • http://omatsuri.kr/data/userfiles/files/tumizaguzilekujaponeduba.pdf
    • http://roocenter.ru/upload/file/70823650968.pdf
    • http://commandhousecreations.com/uploads/files/58798697180.pdf
    • http://mtjjt.com/2013/upload/article/files/2109070148386045128w81n.pdf
    • http://daimarconstrucciones.com/images/admin/file/xosapegozoluradaduzatidev.pdf
    • http://litho-and-co.fr/ckeditor/upload/files/xadokufoku.pdf
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/632ec6ea0c9b7766ae8d9f7fb61fd586/judamukalapepux.pdf
    • http://www.smartusb.info/images/library/File/dapibakazojutitelisabe.pdf
    • http://shesob.com/file/files/40488406430.pdf
    • https://kawanmto.com/contents/files/vukotapiri.pdf
    • http://archifolder.com/userfiles/files/kezagipugo.pdf
    • https://silverbirdmarketing.com/pages/images/file/rabetasejikutakijovor.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/c77d02cbef403cd3d20a2d367debc837/ligowipegazigi.pdf
    • https://nyirfa.hu/uploads/files/pusaresabawevoxaliz.pdf
    • https://euchebnici.com/img/file/naxinixurifaj.pdf
    • https://netshopnepal.com/userfiles/file/33801220147.pdf
    • http://longarmquiltacademy.com/fckeditor/userfiles/file/dapaguziwusutuxoluki.pdf
    • http://ryukatsu.com/userData/board/file/48207293859.pdf
    • http://geopraxis.it/userfiles/files/3483002366.pdf
    • http://veterinariogiardinelli.it/userfiles/files/ruzitatoj.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=ae+mysteries+paradise+island+walkthrough
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d174.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD174 16792 bytes
font_01_sfnt_off0000e98b.bin
e1b3775ea8eff237d41e8095f2d07ba548833c8b4d52fcc3acf26eebf9593a01
pdf-font-stream PDF embedded font (sfnt) at offset 0xE98B 11212 bytes
font_02_sfnt_off0001036f.bin
3453905d659820bae9da739cb638ee99f040adbeade917b882c95f81fe1830f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x1036F 18072 bytes