Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa50e83b173d5b70…

MALICIOUS

PDF

77.5 KB Created: 2021-09-11 14:55:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: c47ae302365613f7d0d4a6efd6373640 SHA-1: 1daa09d484730591683a31eb497e03222ebb6b18 SHA-256: aa50e83b173d5b708706b3193e117438040ef1db3ec2b0fed466f66c7eb94e40
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to various PDF files hosted on potentially disposable domains, indicating a link farm designed to distribute further malicious content or phish users. The presence of external URIs and the link farm heuristic strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://www.jindatunnel.com/up_files/file/94422082673.pdf In PDF document text
    • http://elma1.ru/!upload/files/19230986121.pdfIn PDF document text
    • http://bakersfield.thepokeluau.com/uploads/files/49380179141.pdfIn PDF document text
    • http://toshiteriyakiburien.com/uploads/files/pimikufajaropibanuf.pdfIn PDF document text
    • http://tencanpowder.com/d/files/33788814917.pdfIn PDF document text
    • https://maydangson.com/vietkiendo/upload/file/30475496226.pdfIn PDF document text
    • http://111-orte.de/testarea/cwsCMSlight/media/files/zubesariwigomel.pdfIn PDF document text
    • http://sumbulefendiegitimvakfi.com/resimler/files/12156650233.pdfIn PDF document text
    • http://tupnate.com/ckfinder/userfiles/files/50094359229.pdfIn PDF document text
    • http://xn--80aejmo0alc.xn--p1ai/ckfinder/userfiles/files/jobax.pdfIn PDF document text
    • https://globaltranslation.com/demo/global_translation/beta/userfiles/files/37425886521.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/c483adbd3c4c3da0126920e44528a447/ruxan.pdfIn PDF document text
    • https://ver9.sonikgps.com/ckfinder/userfiles/files/33682736294.pdfIn PDF document text
    • http://www.guus.edu.mn/ckfinder/userfiles/files/sinewaxewimosomeme.pdfIn PDF document text
    • http://namthangbasaltstone.com/uploads/image/files/69568737170.pdfIn PDF document text
    • http://antansconstructions.com/ckfinder/userfiles/files/perefex.pdfIn PDF document text
    • http://hairfibers24.com/upload/file/soxatogolunat.pdfIn PDF document text
    • http://qianlong99.org/ckfinder/userfiles/files/92469008518.pdfIn PDF document text
    • http://anthonyvienna.com/sites/default/files/file/lazosakibu.pdfIn PDF document text
    • https://eccdc.org/application/webroot/userfiles/file/85475289262.pdfIn PDF document text
    • https://mgrenginiai.lt/ckfinder/userfiles/files/21610601466.pdfIn PDF document text
    • http://rcot.by/pics/files/kujoxire.pdfIn PDF document text
    • http://savaksangida.com/resimler/files/84561171490.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16132dd7eaa4c9---33653376547.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=naruto+shippuden+ultimate+ninja+storm+android+downloadPDF 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
stream_004_off0000f658.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xF658 10948 bytes
SHA-256: 1cd8610bbca7081d2f62c2d826c887b64fc91f9bc9c658065ca1e802b8be2206
font_00_sfnt_off0000c632.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC632 18548 bytes
SHA-256: daa6b05e55ce640f2b0213d8f9a8af285abc55554fd5ba25ea215ade28b36ef4
font_02_sfnt_off00010f8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F8F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1