Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc8901b7716b68e9…

MALICIOUS

PDF

79.0 KB Created: 2021-09-26 16:46:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: abecf155f22df93f4a6f3a0f18a973a6 SHA-1: 1ee3362b042434b27e8b3e6b07951dc736badae3 SHA-256: dc8901b7716b68e90078d9b24727284953f38f7f7d372186f8b91c9be6e01869
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF that contains numerous embedded URLs, many of which are part of a link farm on disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a spearphishing attachment, likely leading to further malicious content or exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ketchas.ru/uplcv?utm_term=karp%27s+cell+and+molecular+biology+concepts+and+experiments+8th+edition+pdf PDF link annotation
    • http://thesnowmanicecream.com/ckfinder/userfiles/files/33139764311.pdfIn PDF document text
    • https://paklya.su/design/img/upload/file/suwomo.pdfIn PDF document text
    • http://euro520.net/userfiles/file/1631710325609554380.pdfIn PDF document text
    • http://turnyras.lt/Files/file/zuvanutaparolewinidapu.pdfIn PDF document text
    • https://wildnaturetravel.com/File/zuwowosudam.pdfIn PDF document text
    • http://drzwiukryte.pl/userfiles/file/zowijod.pdfIn PDF document text
    • https://jnnjhansi.com/userfiles/file/50396201187.pdfIn PDF document text
    • http://vasekurzy.cz/userfiles/file/61780781683.pdfIn PDF document text
    • http://magyaringatlanadatbazis.hu/dev/_user/file/63906783452.pdfIn PDF document text
    • https://bodegoncriollo.com/userfiles/file/65136543613.pdfIn PDF document text
    • https://wrd13.com/force/file/fexafejajagegowumopagofa.pdfIn PDF document text
    • http://tjjjsh.com/uploads/files/77437468010.pdfIn PDF document text
    • https://penzion-palice.cz/content/10805811621.pdfIn PDF document text
    • http://hgbs.de/userfiles/file/90525206721.pdfIn PDF document text
    • http://atrsara.ir/resource/files/62173092740.pdfIn PDF document text
    • http://www.its-dph.cz/admin/fckeditor/editor/userfiles/file/legowalotin.pdfIn PDF document text
    • http://kor-ra.ru/UserFiles/file/29314144481.pdfIn PDF document text
    • https://artbynela.com/uploads/file/40132077743.pdfIn PDF document text
    • http://lsphc.com/userfiles/file///tapiliriduxiwikigo.pdfIn PDF document text
    • http://joyandwowbook.com/upload/file/begevilerakiwovaz.pdfIn PDF document text
    • http://ok-poland.com/userfiles/file/jutokodonuvoxesa.pdfIn PDF document text
    • http://constantemails.com/userfiles/file/163229988475396346239.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/ruwafido.pdfIn PDF document text
    • https://kaplaitalia.it/userfiles/files/11483713103.pdfIn PDF document text
    • https://web-dev.ethioapp.com/websites/lightyearsahead/code/userfiles/files/14171056113.pdfIn PDF document text
    • https://razredna-nastava.net/files/58495737385.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614fbfc754955---wewojiboxuw.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_off0000c533.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC533 19768 bytes
SHA-256: 14fa5980753514deaf5fc7f7d17430cf86c6cb9b70ab3ae8fd95c72596678992
font_01_sfnt_off0000f916.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF916 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001112d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1112D 11756 bytes
SHA-256: 4d1f33983ae7636eea5cc089242ebdf7fb6fd1afa70cb29790fc8ad6ddf02140