Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e31ea338730479e…

MALICIOUS

PDF

86.5 KB Created: 2021-09-22 09:44:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: bbcf04be539d6a940f1ae2f36eadcd56 SHA-1: 6501304e421211f40f32a413f3ac01b8c980c873 SHA-256: 4e31ea338730479e6a2620cd2ca5aa9e713baaeb286c670722789b60530ad23e
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with high-severity heuristics indicating the presence of algorithmically generated URLs and a link farm on disposable hosting. The document body is heavily obfuscated, but the numerous external URLs suggest a phishing or malware distribution attempt, likely delivered as a spearphishing attachment. No scripts were extracted, limiting the ability to determine specific execution techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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
  • 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://archism.ru/uplcv?utm_term=samsung+android+dibawah+3+juta PDF link annotation
    • https://mycocoa.org/images/upload/files/basadilusebumifulabesaj.pdfIn PDF document text
    • https://ph2020.org/ckfinder/userfiles/files/kexinu.pdfIn PDF document text
    • http://www.jobibon.com/admin/userfiles/file/46083471337.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/21162972782.pdfIn PDF document text
    • http://polins.org/public/userfiles/file/metevokobijoger.pdfIn PDF document text
    • http://niktid.ru/userfiles/file/54019060894.pdfIn PDF document text
    • http://manpukulivermore.com/uploads/files/99888479024.pdfIn PDF document text
    • https://ladangmimpi2.com/contents/files/felusenoga.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/47124896116.pdfIn PDF document text
    • https://astdubai.co/userfiles/files/27722125750.pdfIn PDF document text
    • http://ambulatorioveterinariosantanna.eu/userfiles/files/43947017979.pdfIn PDF document text
    • https://youkuvpn.com/upload/files/69724824832.pdfIn PDF document text
    • http://skupka23.ru/upload/m/90026450620.pdfIn PDF document text
    • https://s-h.cc/uploads/files/202109162307508230.pdfIn PDF document text
    • https://limsurempat.com/contents/files/xizimefiwefobonekavala.pdfIn PDF document text
    • http://meteoratourismactivities.com/files/files/fawovepolegatusodowoj.pdfIn PDF document text
    • http://studiotecnicoligioni.com/userfiles/files/sexevunelemolelumigiz.pdfIn PDF document text
    • http://studiotecnicodavico.eu/userfiles/files/bexapazif.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/161492b9e756de---53455999741.pdfIn PDF document text
    • http://grawerlik.pl/userfiles/file/tawuvifo.pdfIn PDF document text
    • https://www.autopsrus.com/ckfinder/userfiles/files/dafexavuviwukaxovi.pdfIn PDF document text
    • http://venkateshservices.com/uploads/14888200694.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/850b43d5b2db294dc93d63fda63d6bd1/80044219060.pdfIn PDF document text
    • http://w.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/ronaxaxuxowerosibax.pdfIn PDF document text
    • http://dierenwinkelindex.nl/images/uploads/20271877831.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109050605225461.pdfIn PDF document text
    • http://tribo.kz/userfiles/File/wifotinukumafikadolujev.pdfIn PDF document text
    • https://atiksigorta.com/files/ruzefawerizuzufodim.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_off0000eeda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEDA 11220 bytes
SHA-256: f7eef2dcb5e1a45aeed2dd9023fa66fcb79f5484bcb2316458c91dd86495d4ce
font_01_sfnt_off000108c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108C0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000120d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120D2 16656 bytes
SHA-256: 56b34c2f92ee4d7600e6354452832c2187af0ce700ca2e5c78ba0691bc80d690