Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f2573e2ac73c344…

MALICIOUS

PDF

83.3 KB Created: 2021-09-17 21:46:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 21918fbc422d7550a7475205158117c8 SHA-1: 7307b11043989a0d7ae284d285ec31e123a229ef SHA-256: 5f2573e2ac73c344276deeacc4f5cf7298f6c2dfd1c2e6e6c8c6426b3a8c5d4b
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, exhibiting characteristics of a phishing or malware distribution lure. Heuristics indicate a malformed exploit stream and that the PDF functions as a link farm on disposable hosting, directing users to external URLs. The presence of numerous embedded URLs, including one pointing to 'laborke.ru', suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://laborke.ru/uplcv?utm_term=privacy+protection+password+for+android PDF link annotation
    • http://kasintorn.com/images/upload/files/62668280075.pdfIn PDF document text
    • http://fruhmann-elektrotechnik.at/91228553749.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16142039a7a333---jesurala.pdfIn PDF document text
    • http://a2hgghk.handylover.com/upload/files/48788516254.pdfIn PDF document text
    • https://x-leather.com/radsportfiles/file/selukaxifiner.pdfIn PDF document text
    • https://lapalettedesarts.fr/gestion/file/moxewitabimo.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/iuu6c5thjq4pkq01n8ckt1lnu4/83764494207.pdfIn PDF document text
    • https://cafesca.mx/ckfinder/userfiles/files/11577263132.pdfIn PDF document text
    • https://maxflowfans.com/userfiles/file/30690512799.pdfIn PDF document text
    • https://wroclawmodelshow.pl/ckfinder/userfiles/files/65893212230.pdfIn PDF document text
    • http://aromamahabaleshwar.com/ckfinder/userfiles/files/pasikomozu.pdfIn PDF document text
    • http://mayinmaunhat.com/upload/files/15531160864.pdfIn PDF document text
    • http://czytamzezrozumieniem.pl/userfiles/file/xetamasikomadilorix.pdfIn PDF document text
    • https://ikima.fr/uploads/file/42867965946.pdfIn PDF document text
    • https://hostsolutions.ro/app/webroot/files/userfiles/files/33508081871.pdfIn PDF document text
    • http://nelly-design.ru/upload/files/kadas.pdfIn PDF document text
    • http://samocvet.org/foto/ck/files/buzuxezodonakexugimu.pdfIn PDF document text
    • http://togclick.com/media/userFckfiles/file/29207672925.pdfIn PDF document text
    • https://ottopianos.nl/files/60191243761.pdfIn PDF document text
    • https://chowdhurytourism.com/ckfinder/userfiles/files/xugirekegixoz.pdfIn PDF document text
    • http://12shio5.com/contents/files/68524185681.pdfIn PDF document text
    • https://harmony-lazienka.pl/Upload/file/10805282311.pdfIn PDF document text
    • http://www.tramag.pl/upload/file/29594761708.pdfIn PDF document text
    • http://www.museopizarra.com/ckfinder/userfiles/files/nosipodezo.pdfIn PDF document text
    • http://pathtojanna.com/userfiles/files/88504583001.pdfIn PDF document text
    • http://velomagazin.hu/UserFiles/file/rikiwatokenemomobukekirob.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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC43 10836 bytes
SHA-256: 0d5a91ae62a2061485107a8c9e54cdf63485811a7c73da0fb010efbeabc16885
font_01_sfnt_off0000f585.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF585 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010d97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D97 18908 bytes
SHA-256: 5ec39386f1c4aa7b9b007ce9269967754cb5672183fc377f4d4f8d36a8ff7327