Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b8d870427c07be3…

MALICIOUS

PDF

69.9 KB Created: 2021-10-01 13:31:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 870668a7180d005f6ea32ea80ff2dcd8 SHA-1: 7dd56b1eb3af2c789ddfd91d8f87d94ac9cba8bc SHA-256: 9b8d870427c07be31bf17a740670f87a29f8fe6b9af92fceef4b56e1715ff498
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by a machine learning classifier and ClamAV as malicious, with specific heuristics indicating it is a callback phishing lure. The document body is heavily obfuscated, but the presence of numerous embedded URLs, many pointing to potentially disposable domains, suggests a link farm or phishing infrastructure. No scripts were extracted, but the PDF structure and heuristics point towards a phishing attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/49801307077.pdf In PDF document text
    • http://architettobotteonpierpaolostudioabacus.it/userfiles/files/novugexabemutare.pdfIn PDF document text
    • http://magyaringatlanadatbazis.hu/dev/_user/file/kiwuzedafasozafijipatini.pdfIn PDF document text
    • http://diplomat2014.ru/ckfinder/userfiles/files/8421722304.pdfIn PDF document text
    • http://tns-china.cn/editor_upload_image/file/33402283083.pdfIn PDF document text
    • http://haiphongcontest.com/images/files/soripa.pdfIn PDF document text
    • https://lyna-garage.com/htdocs/cljr/data/files/dopadulukosawesosoz.pdfIn PDF document text
    • https://armenia4d.com/contents/files/fowidanasuniwukegejijeves.pdfIn PDF document text
    • http://schokoladenfontaene.de/idata/47379516221.pdfIn PDF document text
    • http://solemarservizi.it/userfiles/files/fujagelos.pdfIn PDF document text
    • http://floridare.ru/app/webroot/img/uploads/file/365504_pafopukimid.pdfIn PDF document text
    • https://ccenter.ro/userfiles/files/pivuxilelufetokasuzud.pdfIn PDF document text
    • http://luxcottage.ru/stroykamen/userfiles/files/wigaseko.pdfIn PDF document text
    • https://sma-dfgg.org/site/admin/file/69060076781.pdfIn PDF document text
    • http://ybshajiang.com/userfiles/file/2021-09-06/210906235432595889vlz7sae8yxhe.pdfIn PDF document text
    • https://ccveg.org/wp-content/plugins/super-forms/uploads/php/files/ql6dunoar2vdpts9938glj1vfg/tulemamopoberixodo.pdfIn PDF document text
    • https://sportscientistsviews.ijmsir.com/ckfinder/userfiles/files/sumalidozek.pdfIn PDF document text
    • http://detaycopymatbaa.com/userfiles/file/mamunolofikajux.pdfIn PDF document text
    • http://kimsanghun.com/upload/userfiles/file/20219221550103244.pdfIn PDF document text
    • https://phukienbep.net/media/files/vasezofeperevidudof.pdfIn PDF document text
    • http://excitechem.com/userfiles/file/zuxomoxor.pdfIn PDF document text
    • https://partnyor.az/userfiles/file/furiledinaxedadubu.pdfIn PDF document text
    • https://springkasteelhuren.be/userfiles/file/mazesusiromufogegef.pdfIn PDF document text
    • http://kim-clark.ru/files/file/tasamef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=how+to+remove+the+google+account+from+android+phonePDF link annotation
    • 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_off0000b2ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB01 14632 bytes
SHA-256: 11c53f304fdece859c25863bb06d4f4bb384933e83ba6a7a6928eca063a1f8b5
font_02_sfnt_off0000efc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC3 11140 bytes
SHA-256: 4ca2dae7618a7ac3aecaa3cf33081738660d70ea97faacccfb6924e29d43a76e