Malicious PDF — malware analysis report

Static analysis result for SHA-256 5334b66bde8a559a…

MALICIOUS

PDF

77.1 KB Created: 2021-09-16 10:44:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: c623b76c0c1df07c4b221e4442a9c26b SHA-1: ab18c1fd371a3047e4cd3371dffe2f404a0bc00b SHA-256: 5334b66bde8a559a383c5eb63f392ed8d1e18eda1ee19230f85332675dd872b7
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple external links, with one heuristic specifically flagging a link to an algorithmically-generated URL on a suspicious domain. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it is designed to redirect users to potentially malicious content, likely as part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • 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.
  • 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://boucherienabli.com/uploads/FCK_files/file/fetodaje.pdf In PDF document text
    • https://cian.hr/userfiles/file/80142770737.pdfIn PDF document text
    • https://chung-pei.com/userfiles/file/92731062609.pdfIn PDF document text
    • https://mauspro.net/upload/files/22859400184.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613790aa21db1---34259884424.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/wuwejerovikedenezivon.pdfIn PDF document text
    • http://akvari-um.ru/userfiles/file/malubaxaxelevisovavemalof.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613526f84653b---wunufavatenikujajela.pdfIn PDF document text
    • http://gerocuki.hu/user/file/72060666369.pdfIn PDF document text
    • https://superiorservicesandsolutionsfl.com/nbloom/fckuploads/file/52430867887.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/nitede.pdfIn PDF document text
    • http://rockhouseschool.com/rockhouse/uploads/files/rawinizojigaxibolimolixu.pdfIn PDF document text
    • http://klubalfa.org/img/userfiles/file/mujolumajozizusati.pdfIn PDF document text
    • http://commandhousecreations.com/uploads/files/wamifivexodesudujitokadel.pdfIn PDF document text
    • https://pharmnet.cz/ckfiles/files/files/ninogojazi.pdfIn PDF document text
    • http://sandsflooring.co.uk/ckfinder/userfiles/files/donuturobipigexokup.pdfIn PDF document text
    • http://www.saveurspoitoucharentes.com/admin/ckfinder/userfiles/files/safumezedivasimalajubus.pdfIn PDF document text
    • http://aytekinpolatel.com/image/files/gugedibubobexewebori.pdfIn PDF document text
    • http://lisaarkin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jividunumoxaxew.pdfIn PDF document text
    • https://cnn-logistics.com/asset/files/wikejitiresegobogesovatu.pdfIn PDF document text
    • http://bsbcarpet.com/userfiles/file/gilezul.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=bad+ice+cream+mobilePDF 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_off0000c96d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC96D 10352 bytes
SHA-256: ba33288af30147e591253eeb44a86e5b49639c4e1ebfbd3a878c98d850775a77
font_01_sfnt_off0000e0bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0BD 17280 bytes
SHA-256: 0aea0b4ae8d4f37e878d294939cc7f34a1a45682d82af89d2c6231cfd430dc1c
font_02_sfnt_off00010d62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D62 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1