Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b76d3a22742e144…

MALICIOUS

PDF

76.3 KB Created: 2021-09-13 10:46:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 80180871c6908103e9edc3d9261f767b SHA-1: a70d3b854247d0a968181396e209b6a4ca1a60e4 SHA-256: 7b76d3a22742e1445c14e7c8382ed52bf30833aeefc263a7ed4b1c9aab836b39
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by multiple heuristics as malicious, including a high ML score and ClamAV detection as a phishing trojan. It contains numerous external links, many pointing to disposable domains, suggesting a link farm or phishing lure. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of small PDFs acting as link farms on disposable hosting, further supporting the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://coherence.cz/userfiles/file/15887503505.pdf In PDF document text
    • http://belgium-ex.com/images/blog/file/30942379409.pdfIn PDF document text
    • http://synergytaekwondo.com/click2buy_newp/userfiles/file/wodogolojoluzobafizote.pdfIn PDF document text
    • https://duocvinhkim.com/userfiles/file/36341189486.pdfIn PDF document text
    • http://pkpneu.cz/userfiles/file/kukopof.pdfIn PDF document text
    • http://oreoltour.ru/sites/default/files/file/65507338625.pdfIn PDF document text
    • http://cosmikkino.ru/sadm_files/39602424444.pdfIn PDF document text
    • https://ehbo-oostkapelle.nl/userfiles/file/botodelalefudi.pdfIn PDF document text
    • https://eagleegg5k.com/ckfinder/triplebuserfiles/file/tebinafapoz.pdfIn PDF document text
    • http://oembag.com/uploads/files/202109042153415837.pdfIn PDF document text
    • https://wojczak.pl/userfiles/file/74601576825.pdfIn PDF document text
    • https://dollarplus98.com/images/upload/files/11859370359.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/46252df4529ab06a43eb81070a24dc86/11447827077.pdfIn PDF document text
    • http://topliving.sk/userfiles/file/kevipevezigigemanad.pdfIn PDF document text
    • https://kotypsy.pl/ckfinder/userfiles/files/pinemuwubujefekepifijadof.pdfIn PDF document text
    • http://piazzademarini3ge.com/userfiles/files/49822634418.pdfIn PDF document text
    • http://mrcubezpieczenia.pl/app/webroot/media/files/42781153853.pdfIn PDF document text
    • http://esllearningbydesign.com/app/webroot/files/file/zaxapija.pdfIn PDF document text
    • http://kamnitikamini.si/upload/files/91084447805.pdfIn PDF document text
    • https://die-elke.de/cms/elke_page_files/file/suruziwab.pdfIn PDF document text
    • http://hbaoge.com/upload/files/7279528143.pdfIn PDF document text
    • http://fosterfreezesantarosa.com/uploads/files/pipaxarozuloroze.pdfIn PDF document text
    • https://plantbiochem.com/ckfinder/userfiles/files/71235873876.pdfIn PDF document text
    • http://petra-dario.info/upload/datoteke/41219218823.pdfIn PDF document text
    • http://slkuang.com/v15/Upload/file/2021910955274316.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=prem+ratan+dhan+payo+full+movie+download+480p+openloadPDF 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_off0000c371.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC371 16764 bytes
SHA-256: 0e134a7db41216bb1c3884c38ca90974452f14fd95ec82d72da8c11debc4719f
font_01_sfnt_off0000eec3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEC3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000106da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106DA 11368 bytes
SHA-256: 5e15ecfc2778e274c805f364873797ddda300664d452fd8090b0324e3b0ae832