Malicious PDF — malware analysis report

Static analysis result for SHA-256 88fb347b6128af34…

MALICIOUS

PDF

81.0 KB Created: 2021-09-08 21:30:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 94768e5918f818e11890dd2c4dfe665d SHA-1: e2dead0d4d2b435ec9756edd34977edbaa73aed1 SHA-256: 88fb347b6128af34f22550c05bd84f2d61555863e4421675dc4e7899a5db7de2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://allytemp.ru/uplcv?utm_term=brain+teasers+for+high+school+students+worksheets PDF link annotation
    • http://xn----itbbfrdrdbd4bgy6gi.xn--p1ai/webroot/files/files/72406050888.pdfIn PDF document text
    • http://wjvanderheidedienstverlening.nl/uploads/file/5561759321.pdfIn PDF document text
    • http://markone-tools.com/upload/files/tibukimugerojumema.pdfIn PDF document text
    • https://cambodiaangkorhomestay.com/userfiles/file/38387127234.pdfIn PDF document text
    • http://cosmoscm.com/contents/files/13254759145.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/pupemenozuwewedorinedozuj.pdfIn PDF document text
    • http://www.andreapondika.cz/file/16362972144.pdfIn PDF document text
    • https://speculatio.in/ci/userfiles/files/sezak.pdfIn PDF document text
    • http://notar-frings.de/userfiles/file/36070752339.pdfIn PDF document text
    • https://kimcert.net/E/file/51965564184.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138c884e3e25---48683374196.pdfIn PDF document text
    • http://cloverdiamond.com/file/vuwinirasewupuzuzivi.pdfIn PDF document text
    • http://oishisushigd.com/uploads/files/zisuborevonuz.pdfIn PDF document text
    • https://equantumconsulting.com/files/files/5472515533.pdfIn PDF document text
    • http://shortguycentral.com/ck_uploads/files/13722582618.pdfIn PDF document text
    • http://clinton.abwingsmd.com/uploads/files/vepoxelafuxi.pdfIn PDF document text
    • http://anpharma.net/upload/files/vobemerafaduwipefotabin.pdfIn PDF document text
    • http://ichieh.tw/uploads/files/202109032328302730.pdfIn PDF document text
    • https://bdprescription.com/ci/userfiles/files/xagaligenenabelatuvofonu.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/kixax.pdfIn PDF document text
    • https://fratellifurloni.it/file/vojivebodaxakodorebos.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/29012177841.pdfIn PDF document text
    • http://safarang.com/basefile/files/67498158089.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/8f006296a198fdf0f743011c3ddee74e/nelujisix.pdfIn PDF document text
    • http://suamayin.biz/userfiles/file/dumatiminizogozotetosod.pdfIn PDF document text
    • http://kasaitogo.com/uploads/files/1925947045.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_off0000d304.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD304 11088 bytes
SHA-256: 52e8577035766ff04b56c03e27710bc33d61c1bf43c77238a61fdd642d818327
font_01_sfnt_off0000ecac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECAC 18200 bytes
SHA-256: 4b1687b0b565624de4be7fe9e9366ee56eb06ace0401c11b09d70e3bd79c4b7a
font_02_sfnt_off00011bf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BF9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1