Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b1735d5c8606f68…

MALICIOUS

PDF

107.5 KB Created: 2021-06-27 20:41:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: bd0437902ae070dc8e1f5386ef15e3a9 SHA-1: 1d97af5fd84f7e1f2f74975b8fd19e28566fa93e SHA-256: 8b1735d5c8606f68b4f916b21b94ac3f7a3c3732615547ce4baa790e5b3e235f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9639

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 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://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a822584cc59---xilukefifumefalo.pdf In PDF document text
    • http://kondicionery-ivanteevka.ru/upload_picture/file/98104867856.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/loxewuj.pdfIn PDF document text
    • http://jucal.es/images/file/masezep.pdfIn PDF document text
    • https://pet-fashion.ro/mm/file/godakubefaj.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16074cb5dce7f1---38386554420.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cc2efcb9587---puzewese.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160c918e61e313---lotafawifosa.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e5d6d8429ecf50232fcf93631780e1f2/15637512293.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/hfqj08rcubu488tuhgtc4p974m/65711502191.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/q6dirhfkpmm4lihi0ksfi78v6h/fazagusovogivazejoti.pdfIn PDF document text
    • http://colegiosantarosa.com/uploads/imagem/file/kokut.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/9272526b498c7898c19ff6224a5746de/pemapuwal.pdfIn PDF document text
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075afacadac5---39177180532.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d010e8f466---95173910763.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609496f9bb3d6---xaxugo.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/i4pnrsm2ohq7srck0298apoe3j/11551899440.pdfIn PDF document text
    • http://kiemtoanhaiphong.vn/upload/files/36346780989.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609a6ace63fb1---soginetabudon.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071efd2c64e1---60036393891.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/160c97c8fe1049---sodotizowanotagi.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160810f6db830e---kasagawe.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/ellt84bah6sg4ui2pqui8brhe5/31457356450.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/16090dfcbbe0d8---zonur.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/vjm82huv4t8uu5o9j2eh77t230/nilesalujiwaruliw.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6adc73454a---58224538272.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/649cb083e75f32dd552df1ad6986bebf/72406446435.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=meaning+of+appendages+in+biologyPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000127cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127CC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013fe3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FE3 10724 bytes
SHA-256: eeb7128021e39c43e4fffa4bc3d68925e2027b63a62b7b2a434d598b827592b6
font_02_sfnt_off00015828.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15828 19400 bytes
SHA-256: d22d58085d0b51524f4b8f5059656dfcbb59853739cc26455c4c2b5450f28509
font_03_sfnt_off00018b17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18B17 16060 bytes
SHA-256: 8bfc5e2f6383778b4716e60c732a7e5228106b692ca52c1f6b3c0b2892049825