Malicious PDF — malware analysis report

Static analysis result for SHA-256 87c1d80c9bd71f3e…

MALICIOUS

PDF

73.4 KB Created: 2021-09-26 20:01:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 8620bc52fe6d3bd2d37bde086087cccd SHA-1: 3c8c27dc793e0f1193e0abf39b8e77396c53aa10 SHA-256: 87c1d80c9bd71f3ea8b99dc36afe686477598524a61fc32fbd5e17a2f9e07511
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to unknown or suspicious domains, suggesting a phishing or link-farming attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the malformed stream length heuristic and the sheer volume of links suggest an attempt to exploit PDF vulnerabilities or redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9828

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
  • 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.
  • 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://x-leather.com/radsportfiles/file/33770104298.pdf In PDF document text
    • http://lineshare.net/upload/files/20210914082440.pdfIn PDF document text
    • http://domosplast.hu/files/file/45211981555.pdfIn PDF document text
    • https://corpeverest.com/ckfinder/userfiles/files/redurawukisifij.pdfIn PDF document text
    • https://poulinstrapscan.com/userfiles/file/78119684089.pdfIn PDF document text
    • http://guanzhuli.com/userfiles/file/zujug.pdfIn PDF document text
    • http://montpellier-business-plan.eu/mbp/upload/images/images/upload/ckfinder/46791119159.pdfIn PDF document text
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/bukizazirunuziwa.pdfIn PDF document text
    • https://cakesandcupcakes.net/userfiles/files/padupivirutegujupefe.pdfIn PDF document text
    • http://manilag.com/FileData/ckfinder/files/20210902_FA5C748E96D0FAEB.pdfIn PDF document text
    • https://comfort8889.com/upload/files/kobujuzelekevadanonu.pdfIn PDF document text
    • http://firstcuwire.com/file_media/file_image/file/90597388314.pdfIn PDF document text
    • https://emtracing.net/userfiles/file/46980226182.pdfIn PDF document text
    • https://rajatotogroup2.com/contents/files/21410538749.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/4af822ef25e82c37c209229f6c352f7b/66478015273.pdfIn PDF document text
    • https://npkfertilizerproduction.com/d/files/32004095715.pdfIn PDF document text
    • http://vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/fovafopitobasone.pdfIn PDF document text
    • http://groupkaishan.com/d/files/38024399590.pdfIn PDF document text
    • http://cermak-expo.cz/data/files/file/77626814141.pdfIn PDF document text
    • https://jobtiara.com/files/files/bemajel.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613dae5870976---fomamuruwowilovikira.pdfIn PDF document text
    • http://www.andreapondika.cz/file/41239019658.pdfIn PDF document text
    • http://katela.net/userData/board/file/xagebexatirinezoligezafed.pdfIn PDF document text
    • http://checopharma.com/upload/files/sifoweloremadumedu.pdfIn PDF document text
    • http://fcraregistration.com/UploadedData/file/22902202585.pdfIn PDF document text
    • http://veitali.com/upload/files/44216945371.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=fluid+mechanics+fox+8th+solutions+pdfPDF 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_off0000b5f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5F4 18460 bytes
SHA-256: e5bb6fb93b52c3179b63ea552c0e1e4d5eb2487f95d625ffef88ae2c2d890484
font_01_sfnt_off0000e596.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE596 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fdad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDAD 11172 bytes
SHA-256: 532e2f4410052d877c41dc717d6c7447fcc94a627cbca333a78433001f58351b