Malicious PDF — malware analysis report

Static analysis result for SHA-256 961faa8f56201b0f…

MALICIOUS

PDF

89.0 KB Created: 2021-09-17 21:06:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f7cdcf799ebb4267bdebc6ee8ca91cc3 SHA-1: 05121ebe3714303b2a8565de0b29846ad75d5717 SHA-256: 961faa8f56201b0ffd25e3d3c7d6d5bb255a968ae4477a138306795b870668ed
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, with heuristics indicating malformed streams and a link farm structure. The PDF contains numerous embedded URLs pointing to external PDF files, suggesting a phishing or malware distribution campaign. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with spearphishing attachments designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://granitabrasive.ro/editor_up/bexomiv.pdf In PDF document text
    • https://buffinvestment.com/upload/ckfinder/files/zukiwoxave.pdfIn PDF document text
    • https://fairtradeportal.pl/userfiles/file/kazidadupog.pdfIn PDF document text
    • http://halanmilk.com/upload/files/kilowexopuwujevo.pdfIn PDF document text
    • https://store-connector.com/_upload_bilder/_filemanager/file/44748392974.pdfIn PDF document text
    • https://webmedcentralplus.com/userfiles/file/57788081759.pdfIn PDF document text
    • https://bomando.bomsolar.com/uploadfiles/files/3068181758.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/161442ff292545---67778711705.pdfIn PDF document text
    • https://lasanisports.com/files/fadoki.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/binesipuderijeziz.pdfIn PDF document text
    • https://cubic.is/userfiles/file/mumoziridusebovirawu.pdfIn PDF document text
    • https://educhina.mn/editor/files/91556241912.pdfIn PDF document text
    • http://usagimatur.com/files/others/bovufanisiberobovutonaba.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/4b62343614cdf573da7ac7af38e0d5d1/jamimukagojimagarep.pdfIn PDF document text
    • http://biancoacolori.it/userfiles/files/guwakeg.pdfIn PDF document text
    • https://kccegis.com/upfiles/content/file/20210911144656.pdfIn PDF document text
    • http://cjpharmtech.com/upload/files/palipelajakolunizuved.pdfIn PDF document text
    • http://hnhappiness.com/d/files/pisokolibuk.pdfIn PDF document text
    • http://capmar.eu/userfiles/file/bafivoxel.pdfIn PDF document text
    • https://soechi.net/userfiles/file/13748052135.pdfIn PDF document text
    • http://coolscape.info/images/files/zogor.pdfIn PDF document text
    • https://cezartravel.hu/userfiles/file/gigipid.pdfIn PDF document text
    • http://superfishinglewood.com/uploads/files/puwozomazedafapupa.pdfIn PDF document text
    • http://toshiteriyakiburien.com/uploads/files/jifasogigerajegoxojitek.pdfIn PDF document text
    • https://themis-lex.com/userfiles/files/wiwomexegafavogazewe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=android+app+store+payment+methodsPDF 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_off0000f737.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF737 17832 bytes
SHA-256: f86754ead60db27f7c26593d5f980a6706a240975c834dde204fc44a4da7f8c6
font_01_sfnt_off000125ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125EA 10708 bytes
SHA-256: effc888c070536ae94029d8930c17bb74b1a4c1e434fba185aea2247a659f5a6
font_02_sfnt_off00013e58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E58 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1