Malicious PDF — malware analysis report

Static analysis result for SHA-256 d778f551391ef8f8…

MALICIOUS

PDF

81.5 KB Created: 2021-09-08 01:18:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 31997741c6c1b07ba163df08ff352986 SHA-1: 759581ad1f9c15a545c34cfb9fdbe95182219ec7 SHA-256: d778f551391ef8f87ffefb129242559be46da2a93a90e3065d0631c9f86d72c5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external links, many hosted on disposable domains or compromised WordPress sites, indicating a link farm designed to redirect users to potentially malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. The presence of multiple external URIs and compromised CMS upload links points towards an attempt to distribute or host malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://chcial.ru/uplcv?utm_term=boolean+function+book+pdf PDF link annotation
    • http://terezmisszio.eu/files/file/bovosizebubafox.pdfIn PDF document text
    • http://bukharageorgia.com/sites/default/files/file/pagasitulisuxefakesozu.pdfIn PDF document text
    • http://erainbowrealty.com/userfiles/file/50581470863.pdfIn PDF document text
    • http://basumati.com/app/webroot/ckfinder/userfiles/files/kepepol.pdfIn PDF document text
    • https://topjobsnepal.com/ckfinder/userfiles/files/18606832957.pdfIn PDF document text
    • http://www.johnrealestate.in/ckeditor-ckfinder-integration/uploads/files/62674665399.pdfIn PDF document text
    • http://sushiyaslo.com/uploads/files/86187874845.pdfIn PDF document text
    • https://baglab.pl/galeria/file/80235603873.pdfIn PDF document text
    • http://ledins.lv/cms/file/2384889889.pdfIn PDF document text
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/wegosetuxapomoz.pdfIn PDF document text
    • http://aptwash.com/userData/ebizro_board/file/27776780681.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607909849fccb---sevudasisajamupo.pdfIn PDF document text
    • http://lakshimi-kaatsu.com/user_data/packages/default/imgfiles/pazumateluduxofix.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cc32fc1e8c0---49087091621.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/f4aa6ec6d14f45ff848e837172176aad/6650413173.pdfIn PDF document text
    • http://www.odnpoznan.pl/fotki/file/file/jojamafefalufokuwazodol.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/8ac5031110ad8b1ce5cdd300f88792b4/jizokavibufuzuseke.pdfIn PDF document text
    • http://skupka54.ru/upload/m/21021715654.pdfIn PDF document text
    • http://i-daa-wl.de/userfiles/67730955170.pdfIn PDF document text
    • https://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/7g782a801p93l9pcdakghm6ll2/1210539263.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16087f110690b1---86021278800.pdfIn PDF document text
    • http://gardnersunited.com/clients/e/eb/eb3320446930dd457027df34457c622b/File/wugidini.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e16d74d2c47---xejebexogekifu.pdfIn PDF document text
    • http://cokhihoangvinh.com/uploads/userfiles/file/8587658287.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_off0000d56f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD56F 18612 bytes
SHA-256: c4205f877b222a563d63017afc27a4d68bae5b7500204b47c2a0586b03327431
font_01_sfnt_off0001062b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1062B 10728 bytes
SHA-256: ed28a30678846c47f39c3b857aa72b7eb28451c80208c9107649d2c50fcb1804
font_02_sfnt_off00011eb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EB4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1