Malicious PDF — malware analysis report

Static analysis result for SHA-256 818c88b0ec39bf3b…

MALICIOUS

PDF

88.9 KB Created: 2021-07-05 01:47:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c470c08f6d668586687fdea452d49fd9 SHA-1: f58ca42fd3d3371ec158ab98ec722c3ed3421997 SHA-256: 818c88b0ec39bf3b98ccf507a4414a849b257d799f4e1234095dff5583930c9f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress uploads and disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of attempts to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://contabil-fiscal.ro/mm/file/fasava.pdf In PDF document text
    • http://bangkoksolarpower.com/syner_upload/images/files/rudazibisomigadegezokasa.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073ccbe61fae---buvanakafiva.pdfIn PDF document text
    • https://capitalsyndic.com/userfiles/file/27253860589.pdfIn PDF document text
    • http://teraval.cz/res/file/29267382386.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c4eee44d493---ziroluburibededarux.pdfIn PDF document text
    • http://arunimaflavours.com/userfiles/file/zonif.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/9b3b449af6e8cee236f0268be2e79d2e/26628086207.pdfIn PDF document text
    • http://attep.com/home/sandbox/domains/heekee.com.hk/public_html/ckfinder/userfiles/files/pigivexuxotibolegalir.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/rivukumavulilepobedi.pdfIn PDF document text
    • http://xn--939a66v0zjo3bcvdmrp.com/data/ckfinder/files/41585453435.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/27c0cdda440be8e32c7e91469e78f1b9/jojijinofujeg.pdfIn PDF document text
    • http://naturalmis.com/userfiles/file/6984208030.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a734d77eca6---36439576342.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/b2481e5889727b870265e90da717233e/91504166821.pdfIn PDF document text
    • https://maclashoes.it/file/72437312988.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609bd9080e0f2---wopukuvaro.pdfIn PDF document text
    • https://seitonsolutions.com/ci/files/56428201770.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/db87ece5ca65a62d9b8d386ef2ee8684/tumowuritisinoj.pdfIn PDF document text
    • http://ukuleleceilidh.ca/clients/860383/File/pemojexejifijelogavo.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///3757324757.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/1kg9rc1r8sn7qo4u6uujb5v5s4/xagis.pdfIn PDF document text
    • https://bayardplaza.co.uk/wp-content/plugins/super-forms/uploads/php/files/3bta317kj8sm7nd3pdk3vn2t33/nakemororexodujojuma.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/q8l35vr9pvj07e4ogp82aa6kku/gemixazimosijawi.pdfIn PDF document text
    • https://alsterparkett.de/wp-content/plugins/super-forms/uploads/php/files/on78fi4mi9heuk2k5qv478stlc/42271929370.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=principles+of+layoutPDF 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_off0000f70a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF70A 10688 bytes
SHA-256: 17d1623254c452dd9f9fb10f8ab6f577d02daab88f946e3b7530c29e5ea4da12
font_01_sfnt_off00010faf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FAF 17960 bytes
SHA-256: 50aad0c8295fafd29fa887305720e3f2999e1292d81bc677be3a9f29d51d5c29
font_02_sfnt_off00013e87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E87 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1