Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa5f14bbb6736fe8…

MALICIOUS

PDF

80.4 KB Created: 2021-09-16 19:15:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: c65d31099f154ddffb2f96b4e4b73d19 SHA-1: 84df86b79665cf48ba25e31d6911f2c52a16168b SHA-256: aa5f14bbb6736fe86741b32ef7c71be32f2fd0a90a876db20608f38e5ee55b0c
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm. The document contains numerous embedded URLs, many of which point to PDFs hosted on potentially disposable domains, suggesting an attempt to distribute further malicious content or redirect users to phishing sites. No scripts were extracted, but the overall structure and heuristic firings strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://gomsuhoangminh.com/app/webroot/uploads/files/jugazofatak.pdf In PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614119583768b---59465285561.pdfIn PDF document text
    • http://chayka-svg.ru/files/rijepewa.pdfIn PDF document text
    • http://geologicatoscana.eu/userfiles/files/54710634166.pdfIn PDF document text
    • http://crisismobile.com/ckfinder/userfiles/files/nukijewabigijolanafidavu.pdfIn PDF document text
    • http://patronusalapitvany.hu/public_html/upload/72567176433.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/535f7db9e095db8876ecb283985c4d6f/jonok.pdfIn PDF document text
    • https://norservis.com/files/files/duvogubipikisaponujediv.pdfIn PDF document text
    • http://an-professional.ru/img/files/file/lanukoguzuramifen.pdfIn PDF document text
    • https://condominiovillage.com/userfiles/file/4357616060.pdfIn PDF document text
    • http://crabandclaw.com/uploads/files/14973650183.pdfIn PDF document text
    • http://grupposcorcia.it/userfiles/files/63254852086.pdfIn PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210908130209.pdfIn PDF document text
    • http://sjatupornservices.com/file_media/file_image/file/23851152751.pdfIn PDF document text
    • https://alusol-kw.com/ckfinder/userfiles/files/92677724823.pdfIn PDF document text
    • http://vector-luczak.pl/new/fck_user_files/file/19592227816.pdfIn PDF document text
    • http://boschvietnam.vn/files/usersfiles/files/zupapumevofugapili.pdfIn PDF document text
    • http://olddieselparts.com/ckfinder/userfiles/files/waburijazi.pdfIn PDF document text
    • http://matrix-corporation.com/upfiles/editor/files/16231912740.pdfIn PDF document text
    • https://ww150001.linebot.net/upfile/files/20210908171158.pdfIn PDF document text
    • http://werkschoenenverkoop.nl/images/docman/files/86558470168.pdfIn PDF document text
    • http://www.letnifestiwal.pl/ckfinder/userfiles/files/tujabokikonifuzagumaro.pdfIn PDF document text
    • http://imhome-listings.com/userfiles/files/gewunileromip.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=psychopathy+checklist+youth+versionPDF 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_off0000d34e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD34E 10844 bytes
SHA-256: d2cc1ebf47970118d04cafa4817cc0837dc0882cb6f632daf7dcd6a5bc8cd5ae
font_01_sfnt_off0000ec62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC62 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010474.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10474 18428 bytes
SHA-256: ec9385b1c97af1c653713f7b323534300aff73089b7a07288be5a9079911cd2a