Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4bd77f092f38d29…

MALICIOUS

PDF

153.8 KB Created: 2021-07-01 09:21:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: e95d48ef0371763b00427b26fbbbf9be SHA-1: 1d307cba7a87e9251b0c759fe45ab6f13facac33 SHA-256: b4bd77f092f38d29c7af05150679b4822756abefddf477105ac4a1f56f41405c
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The malformed stream length heuristic also points to exploit activity within the PDF structure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://catamma.ru/uplcv?utm_term=homogeneous+linear+system+calculator PDF link annotation
    • https://studiovizia.com/webroot/img/content/files/18434962837.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c7aade9fdda---guzadas.pdfIn PDF document text
    • http://bizbecho.com/pa/trainstation/uploads/image/file/kivixusosefisegejabemawim.pdfIn PDF document text
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/cf3335a2af8c6fe1639d599d95d391d8/55374761922.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/e16ee746fe6a0dc220b6defffdba4d6e/wavafibasapakofowo.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607de3cac4dd2---42085788459.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/aa2b72fbb65326b2aae4ef2dfdc8d747/82162241564.pdfIn PDF document text
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/ac563c72820baa02652a205bb82cb2e9/75248319062.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/vrl2rl2bm50m628e36ef8hlbi2/fosukuvagatinene.pdfIn PDF document text
    • https://i3mit.com/shopadmin/upload/files/67777688862.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/16085425d82680---75224998911.pdfIn PDF document text
    • http://xiaohecollege.com/d/files/83914056537.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/160c0941b89737---74022790978.pdfIn PDF document text
    • http://bethtikvahevents.ca/clients/2/20/20a91c0cb94b02964b0d1c5d980f1596/File/39086484385.pdfIn PDF document text
    • http://sghscsjamarai.org/guruhargobind/userfiles/file/jutogizizekuximax.pdfIn PDF document text
    • http://megaprestige.ru/uploads/files/66199971310.pdfIn PDF document text
    • http://aqs-group.it/userfiles/files/zelix.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///lupopisupe.pdfIn PDF document text
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1607b7b781c473---mopejojixefomedobimo.pdfIn PDF document text
    • http://jmdfhjl.com/fckeditor/userimages/file/21314282223.pdfIn PDF document text
    • https://ka-base.no/images_content/file/64265011150.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bddefd4d7e8---80474010757.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4d19a9fe34---46183691857.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/7c8dfe1a315c15c06a4350667ad98ff4/40458144897.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3783e90fe2---xukepudixuniwodu.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

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001fa03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1FA03 17700 bytes
SHA-256: d04c7fb35a3b84126f85df0e9fdb3c93025266531b4543b1d80c14a3161153ff
font_01_sfnt_off00022870.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x22870 10776 bytes
SHA-256: 0592b8cca008e6caaef47a6409142b2d05287f6a5947b62ad00b146460ef877e
font_02_sfnt_off00024148.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x24148 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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