Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8ba51e80d95e409…

MALICIOUS

PDF

80.9 KB Created: 2021-09-17 03:51:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2fb582724f6635b2f4b45b9925ce95b5 SHA-1: f5118356c39123f2b0e916161bf2367fdd62a696 SHA-256: f8ba51e80d95e409345d393efd24b32a2cf4d64402741007418643e6388f4b85
126 Risk Score

Malware Insights

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

The PDF contains numerous external links, many of which are hosted on disposable domains and appear to be part of a link farm, a common tactic for phishing or malware distribution. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to malicious websites, likely as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://medvor.ru/uplcv?utm_term=tjoc+r+apk+download+android PDF link annotation
    • https://fidelishospice.com/ckfinder/userfiles/files/57424969444.pdfIn PDF document text
    • http://otczenacts.com/media/files/tupatatixorut.pdfIn PDF document text
    • http://nanopena.cz/upload/file/20522869792.pdfIn PDF document text
    • https://inprovitmexico.com/ckfinder/userfiles/files/jupexuwasifiwoba.pdfIn PDF document text
    • https://profession-your-dr.com/uploads/files/202109122302229379.pdfIn PDF document text
    • https://rowsontw.com/shopadmin/upload/files/gazet.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16140924b9d894---vaziremefigod.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021090705263971.pdfIn PDF document text
    • https://markaoyun.com/calisma2/files/uploads/71682417012.pdfIn PDF document text
    • http://philipwillettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bijarowuregejosevov.pdfIn PDF document text
    • http://linklandhotels.com/upfile/editor/files/limuzo.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/6fae119adc9972800ad5c7bdbfb2b16e/41202253852.pdfIn PDF document text
    • http://jakpaisanestate.com/images/upload/files/tevebebelosowizafijit.pdfIn PDF document text
    • http://scamps.biz/userfiles/file/15710980456.pdfIn PDF document text
    • http://tnslib.tools/userfiles/files/forejifuzurinivejegod.pdfIn PDF document text
    • http://s13cf5ef.alojamientovirtual.com/ropadefutbolbarata/userfiles/file/54458109055.pdfIn PDF document text
    • http://zae.me/datafiles/file/lidebamowakim.pdfIn PDF document text
    • http://eltprof.ru/userfiles/file/92424043821.pdfIn PDF document text
    • https://ezokniga.com/uploads/file/kesojebuvizew.pdfIn PDF document text
    • http://saothienemb.com/uploads/images/files/89814582026.pdfIn PDF document text
    • https://lesrimaudieres.com/images/uploads/file/ravarejina.pdfIn PDF document text
    • https://tfsroanoke.com/home/tfs/public_html/new/ckfinder/userfiles/files/penajudafavuki.pdfIn PDF document text
    • http://youzedu.com/ckimages/files/20210906045153667965.pdfIn PDF document text
    • http://hnc2.com/userfiles/file/rizelisuwutebezile.pdfIn PDF document text
    • http://teamhead.net/userfiles/file/33229668322.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_off0000cb95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB95 10380 bytes
SHA-256: ea53b4e1cecfefb378cef86db4a6902687e00a63b366d4cf473879f9e2553f9d
font_01_sfnt_off0000e31c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE31C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB2E 22660 bytes
SHA-256: 04ced48c98e45475c69957cde4c096e3cf0c446678089464937c714a7b4eca02