Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb138b76ebfc47e6…

MALICIOUS

PDF

68.6 KB Created: 2021-09-30 23:52:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 712e81559742fbe66ac7cf7ae60c45fc SHA-1: 4c00cd7b02a73d414aaecd63432bcd1f6a8384a8 SHA-256: cb138b76ebfc47e693fcc74c56d7c41fc114dd64ff43638452ab530ef386cbeb
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external links, many of which point to disposable domains and are designed to function as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate redirection to these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://infrive.ru/uplcv?utm_term=16+trillion+in+numbers PDF link annotation
    • http://tcsm62.org/uploads/news/file/8098590488.pdfIn PDF document text
    • https://www.tulsarad.com/my_content/js/ckfinder/userfiles/files/75933218586.pdfIn PDF document text
    • http://pozitron-s.ru/userfiles/file/53752286240.pdfIn PDF document text
    • http://tianlanlawyer.com/filespath/files/20210905005314.pdfIn PDF document text
    • http://urs-certification.com/gais/image/file/ximegufekujobenibelazi.pdfIn PDF document text
    • https://webmanagement.produse-electrice.ro/images/file/15377104846.pdfIn PDF document text
    • https://birutelorasin.com/contents/files/kibivow.pdfIn PDF document text
    • https://davidfoleyinc.com/userfiles/file/gubomovituledopozik.pdfIn PDF document text
    • http://badischer-kunstverein.de/ckfinder/userfiles/files/44990810852.pdfIn PDF document text
    • http://demirlermetal.com/resimler/files/xetitozutuzezobotofolal.pdfIn PDF document text
    • http://hurtglass.pl/upload/file/tubeva.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/file/21721279676.pdfIn PDF document text
    • http://tianlanlawyer.com/filespath/files/20210902142441.pdfIn PDF document text
    • http://lukoilmarine.com/ckfinder/userfiles/files/6036945023.pdfIn PDF document text
    • http://sinhorelli.com/userfiles/file/wotuloziwoluwuzuzodowakoj.pdfIn PDF document text
    • https://marcvandewiele.com/userfiles/file/45829095352.pdfIn PDF document text
    • http://jpsacademy.com/slbdavbatala/userfiles/file/bonoxefazaduzizuxidal.pdfIn PDF document text
    • https://askisan.daynexdemo.tk/upload/files/xipezirisetezaxe.pdfIn PDF document text
    • http://murielbellhomes.com/userfiles/files/jimalanaru.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/ogt9e45jvajco42su7s8p8ds43/sedezelanozofuxunuxiguji.pdfIn PDF document text
    • http://okmarin.ru/userfiles/file/85838725350.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_off0000abf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xABF3 16080 bytes
SHA-256: c802da62124760cc3fb203a491a09f292c06cb90149b0e49614e0aa2a8fa1b46
font_01_sfnt_off0000d53a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD53A 10468 bytes
SHA-256: 88ac057447ee36cee279ec6de984ba06479c78d520988a1d42379554afffb133
font_02_sfnt_off0000ed04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED04 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1