Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b6173ed1ef7867a…

MALICIOUS

PDF

69.6 KB Created: 2021-09-28 20:32:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 8bbc791b63d919b9e82a556b0774a2cf SHA-1: d288f417e4ffe4cd04ca3cf738892ca956d35a83 SHA-256: 6b6173ed1ef7867a68149e1c47759ce5ef55939308abec7b454a4296a8fca282
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which point to other PDF files hosted on disposable domains, a common tactic for distributing malicious content or conducting phishing. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm behavior suggest it's designed to lure users into downloading further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://infrive.ru/uplcv?utm_term=sentences+with+ant PDF link annotation
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/161331f090607b---10315175229.pdfIn PDF document text
    • https://naveenent.com/administrator/imagetemp/file/88444487832.pdfIn PDF document text
    • http://constantemails.com/userfiles/file/1632076534sizow.pdfIn PDF document text
    • http://archpiudue.com/userfiles/files/27237025434.pdfIn PDF document text
    • http://originalavto.ru/userfiles/file/bivege.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/wibuvosa.pdfIn PDF document text
    • https://stormester.no/files/file/41411945482.pdfIn PDF document text
    • https://coolinterier.sk/upload/files/57892408311.pdfIn PDF document text
    • http://fuku-zou.com/userfiles/file/2322081143.pdfIn PDF document text
    • http://diskacme.dk/images/upload/file/9616315269.pdfIn PDF document text
    • http://orel-trinity.ru/sites/default/files/file/13136004640.pdfIn PDF document text
    • https://forumsevens.com/images/file/69772097233.pdfIn PDF document text
    • http://xn--80aafbjcazdrhzgiddbbcsg4l.xn--p1ai/pict/file/79143125247.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/xezovunusetolidemog.pdfIn PDF document text
    • https://psicologopsicoterapeutaemdrtorino.it/uploads/file/39844702700.pdfIn PDF document text
    • https://resttour.com/images/userfiles/files/dolelekevigalimonavetitil.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b1e32b4a18e5f812d070897e732f9cbe/jurizipafolufojuvesudap.pdfIn PDF document text
    • http://hoangduy.vn/vn/files/41088946193.pdfIn PDF document text
    • http://share-world.tw/userfiles/file/zabofutejudogo.pdfIn PDF document text
    • http://perfectionistpaintingnj.com/ckfinder/userfiles/files/vugawemajuwimulonixup.pdfIn PDF document text
    • https://vnnc.vn/img-hdmedia/files/zuzizefafo.pdfIn PDF document text
    • http://bscsaoner.in/ckfinder/userfiles/files/zidumawuxetadu.pdfIn PDF document text
    • http://banglenhospital.com/UserFiles/File/xegiba.pdfIn PDF document text
    • http://majorpropertygroup.com/userfiles/files/fofenokibowo.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_off0000b166.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB166 10224 bytes
SHA-256: aa64caae4025379bd795b9272d08ffd17542484414f57c20632f65fccc9ecb7e
font_01_sfnt_off0000c854.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC854 15988 bytes
SHA-256: 0cbd435457be3e04dc526f39bab52d4d4a8114a7526c7d34cea1f30759361153
font_02_sfnt_off0000f0af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1