Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad87d6a5e74c9c08…

MALICIOUS

PDF

81.5 KB Created: 2021-09-11 22:36:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 97651870916a2903d67152f40c545c36 SHA-1: 14aa0366810b67b62332ac895610b3c624b2ab7e SHA-256: ad87d6a5e74c9c08b2f9dc9f0388791b22f4585236ad545a0025ca748693a619
166 Risk Score

Malware Insights

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

The sample is a PDF file that contains multiple links to external PDF documents, many of which are hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of embedded URLs and the PDF_RANDOM_URL_LINK heuristic suggest the document is designed to redirect users to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://fge-service.com/userfiles/file/68458967217.pdf In PDF document text
    • https://tomorrowhubs.com/upload/users/files/wefopilajomilevavofon.pdfIn PDF document text
    • http://ehoron21.mn/uploads/files/bavufejetajuligejipowatir.pdfIn PDF document text
    • http://abwjefferson.com/uploads/files/31330648130.pdfIn PDF document text
    • http://tehla.eu/userfiles/file/runezorexugudixob.pdfIn PDF document text
    • http://gardensyellowcab.com/admin/images/file/wajidebodevotes.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/pasedozusejumusukekegoxi.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/gowosijozavugu.pdfIn PDF document text
    • http://rustproofingottawa.com/userfiles/file/fijizadigifega.pdfIn PDF document text
    • https://holcom-wd.com/webroot/img/files/84683056046.pdfIn PDF document text
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/20783556660.pdfIn PDF document text
    • http://thewhitmerlawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/80281522236.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/3228942241.pdfIn PDF document text
    • http://gestaocipa.com/public_html/Imagens/file/vibududugepalomiwa.pdfIn PDF document text
    • http://surtek.biz/image/files/20150320_102225.pdfIn PDF document text
    • http://lasfyy.com/uploadfile/file/20210901093738948.pdfIn PDF document text
    • https://mtestbd.com/assets/uploads/files/fagatobofetanudodogegigom.pdfIn PDF document text
    • http://meruzhankhachatryan.com/app/webroot/files/file/2860347233.pdfIn PDF document text
    • http://thestarbusan.com/FileData/ckfinder/files/20210911_8978B9907C9F9346.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/416b76fb47ebd8ebeb96660f9abda3a3/50078021939.pdfIn PDF document text
    • http://tongshengchem.com/ckfinder/userfiles/files/75715147585.pdfIn PDF document text
    • http://kbidc.kr/upload/editor/file/1631118933.pdfIn PDF document text
    • http://mecaniquekd.ca/upload/file/xixidajokewukamonotitupar.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=can+i+recover+deleted+text+messages+on+androidPDF 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_off0000d95c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD95C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f16e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF16E 17584 bytes
SHA-256: f1601e0b2352e36853d7442e949545b46e815ad349f4f742c4f9a47ca70eb91b
font_02_sfnt_off00011eea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EEA 10912 bytes
SHA-256: f38cebe6927c8247839d9a6aa50b93529573ebda051a1ff233db50a50603d0f4