Malicious PDF — malware analysis report

Static analysis result for SHA-256 b820921b9d861bfc…

MALICIOUS

PDF

67.9 KB Created: 2021-09-16 17:29:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5c24949946c7a2d2597cde1a2b0a0bf0 SHA-1: cac8530adfcfffb5da634df32f96507741fda9cc SHA-256: b820921b9d861bfc3427cff5de6b6de6ac1e4539727ad2a308fd0f792c57689d
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF is identified as a phishing lure due to its small size, image-heavy content, and embedded clickable actions pointing to external URLs. Heuristics indicate it's a link farm on disposable hosting, suggesting an attempt to distribute malicious content or redirect users to phishing sites. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with common phishing techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 67 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://giaydantuongphongngudep.com/images/news/file/rogudiniki.pdf In PDF document text
    • http://chukysovin.com/img-svc/files/47931820639.pdfIn PDF document text
    • http://stimatacasa.eu/userfiles/files/89029379698.pdfIn PDF document text
    • http://saint-party.com/media/file/janilunabilakib.pdfIn PDF document text
    • http://hoaisonland.vn/upload/files/50381352052.pdfIn PDF document text
    • http://munnarinfo.in/userfiles/file/13434611286.pdfIn PDF document text
    • http://tkhomedeco.com/assets/uploads/ckedit/files/20210905113741.pdfIn PDF document text
    • https://prestinieurope.com/userfiles/files/19630882733.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/mefulomi.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///16124850019.pdfIn PDF document text
    • http://pusancard.com/userData/board/file/wezemiduxasulafower.pdfIn PDF document text
    • http://tw-jia.com/uploads/files/202109071808304702.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/17129748705.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/81724948271.pdfIn PDF document text
    • https://tskrea.com/userfiles/file/vokeriwug.pdfIn PDF document text
    • http://elma-itc.ru/!upload/files/wumam.pdfIn PDF document text
    • http://bajcsidavidfoto.com/_user/file/bopawapabusidokuragoxoz.pdfIn PDF document text
    • https://xn--p3t29jo1ed4o4xw.tw/upload/files/28390791158.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/titixe.pdfIn PDF document text
    • http://futureinfashion.com/ckfinder/userfiles/files/48925628372.pdfIn PDF document text
    • http://tjjjsh.com/uploads/files/suzodulidot.pdfIn PDF document text
    • https://anfauglir.com/images/file/22744661509.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=town+city+apk+modPDF 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_off0000af64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF64 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c77b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC77B 10484 bytes
SHA-256: a443008b6720a0781a746debc938e3b18e985d67363957e9a06d8688b281f285
font_02_sfnt_off0000df69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF69 14068 bytes
SHA-256: d3cbfce9399cbf14bcd22493107d2a3feea012bfc4fb1e7f45da677497746ea6