Malicious PDF — malware analysis report

Static analysis result for SHA-256 1fddb90b8d273d20…

MALICIOUS

PDF

71.8 KB Created: 2021-09-12 23:04:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 874dafd31dfd829a998675da2f8796dc SHA-1: fecceec861c1e72cb9867bb4af4139101e9ffd21 SHA-256: 1fddb90b8d273d20c258130095b418e5c7c2829d17d439f91c8a768c8f9c3a9e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm hosted on compromised WordPress upload storage, with multiple links pointing to potentially malicious PDF files. The presence of external URIs and the nature of the links suggest an attempt to redirect users to download further content, likely malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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 http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613db06f3a1c8---dimadili.pdf In PDF document text
    • http://agataklimowska.pl/userfiles/file/75549969056.pdfIn PDF document text
    • http://nuovojob.com/userfiles/files/gelumepa.pdfIn PDF document text
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/93488678600.pdfIn PDF document text
    • http://agriturismoilnoceto.com/userfiles/files/22985352354.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/zudewiko.pdfIn PDF document text
    • http://entrackintl.com/uploads/41717715645.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139fa816923f---jatowixakajanezava.pdfIn PDF document text
    • http://yesfabric.com/images/upload/File/81589928660.pdfIn PDF document text
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/buxazubetij.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210911185348.pdfIn PDF document text
    • http://www.onlinenieuwsbriefversturen.nl/gebruikers/afbeeldingen/99957424402.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff721cd166---98830381211.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136176ad8e77---warudatomosebixeg.pdfIn PDF document text
    • https://blv.by/upload/editor/files/fuforigitewanizinin.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff51e61c87---91910178595.pdfIn PDF document text
    • http://podhoru.cz/userfiles/file/10908919097.pdfIn PDF document text
    • http://jowinbio.com/upload/files/202109120122473375.pdfIn PDF document text
    • https://kolegium.inaheart.org/upload/files/86138066056.pdfIn PDF document text
    • https://mediaskills.rs/files/walifozonorolixidubo.pdfIn PDF document text
    • http://kqcme.yiaiwang.com.cn/upload/files/mopusujesisav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=free+fire+apk+mod+unlimited+diamonds+and+coinsPDF 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_off0000b6b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cec8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEC8 10948 bytes
SHA-256: b7cd7444ac1cb18bf187eafd132f92a18b02abff0ef200ad98bc925ca0b7a32c
font_02_sfnt_off0000e820.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE820 16360 bytes
SHA-256: 879bbe2a687168117c5095852baae216bad3d4f4dfd94e18f32d553656cfda12