Malicious PDF — malware analysis report

Static analysis result for SHA-256 88e825da3007be77…

MALICIOUS

PDF

88.4 KB Created: 2021-07-08 10:35:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 21e8a5666e0b9e95e0f7f23f5e08a9da SHA-1: 574e0ca17c97d4dc1635c2200e895f5f8f51682d SHA-256: 88e825da3007be778e9956306c8f30c3c03b6484b453ec92f3f5388cf192acfe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identify it as a link farm, with numerous external URLs pointing to potentially compromised websites or disposable hosting. The primary attack pattern involves luring users to these external links, which could lead to phishing or further malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://penzionriverside.cz/files/file/33561461710.pdf In PDF document text
    • http://pensjonatagat.pl/userfiles/file/95568936921.pdfIn PDF document text
    • http://www.thaiboat.net/image/upload/File/39034313217.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609f526b97159---38892937011.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/zusomuxa.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160940566c6bad---sifuvanofabubovatagom.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/6412256bf60a207a8f7e202b1cd14118/jatajesifix.pdfIn PDF document text
    • http://nietegeleuve.nl/cms/files/75366824676.pdfIn PDF document text
    • http://happyland-nsk.net/ckfinder/userfiles/files/16489003423.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/ahbgvodrqnqogaoa6qc72urmlc/95142734641.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/wugexexeromaside.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c88125d2c9d---nuwut.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160bb4b0bc7bd6---3732939597.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/16079b219b4a90---lixad.pdfIn PDF document text
    • http://sculecuacumulator.ro/app/webroot/files/userfiles/files/lipegilimamarabuwikor.pdfIn PDF document text
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a190d2dd505---25250631160.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609427bce8845---28370897328.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608ae7ade0868---38262982433.pdfIn PDF document text
    • http://alphamarino.kz/images/news/file/zokanelekoxozej.pdfIn PDF document text
    • https://bonafideonline.com.ar/wp-content/plugins/super-forms/uploads/php/files/983da059354b22fe8bf25a2f52065df0/futudetosodumotebo.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/ad9109667324bd9d5fe0b24fabdbef60/dikipazegubef.pdfIn PDF document text
    • http://laulumaja.fi/ckfinder/userfiles/files/fimituwafezuz.pdfIn PDF document text
    • https://aplusadvance.com/naver_editor/data/file/zipexuxadusobojaratex.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe83ccf5ba---surotaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=how+do+skeletal+muscles+work+in+pairsPDF 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_off0000f5bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5BF 17092 bytes
SHA-256: 71171686df47f5571b97a04c5fd109128c63bb10f6122dff4f2f617e4fc450f6
font_01_sfnt_off000122a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122A2 10944 bytes
SHA-256: f19f31280815f62e4be69e25655ccf06c55544231d48d9a03d63dc2ea93d9a24
font_02_sfnt_off00013bfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BFE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1