Malicious PDF — malware analysis report

Static analysis result for SHA-256 cea455b78bf3e066…

MALICIOUS

PDF

82.6 KB Created: 2021-09-15 21:01:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2fc307a744dd870e79c0f46f5534a92a SHA-1: 3405c3d270264135c91bcaae62ee62c5e1c39b95 SHA-256: cea455b78bf3e0663041e3871e2002b4a21845959bf0e2a50ce1027e1e1540a4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to disposable hosting, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • 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.
  • 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=pdf+english+pronunciation+in+use PDF link annotation
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613838d964f89---83309452853.pdfIn PDF document text
    • http://mansiya.com/uploadfile/files/jafepab.pdfIn PDF document text
    • http://lechioutdoor.com/userfiles/file/fekolo.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/98sjrge2ajtrkgt4t3mhhavsq1/76269895548.pdfIn PDF document text
    • https://emilline.dk/ckfinder/userfiles/files/23184646435.pdfIn PDF document text
    • http://fecirturizm.com/resimler/files/87729702715.pdfIn PDF document text
    • http://bzws.zhanyougame.com/ckfinder/userfiles/files/wuvefakadi.pdfIn PDF document text
    • http://tweedehandswikkelaar.nl/app/webroot/files/userfiles/files/14600409613.pdfIn PDF document text
    • http://pokeocncafe.com/uploads/files/59708511263.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/nevolodenibolomiralosel.pdfIn PDF document text
    • https://icrs-as.com/userfiles/file/40148655972.pdfIn PDF document text
    • https://innovativallatgyogyszer.hu/fileok/file/koxerajuvanesaf.pdfIn PDF document text
    • http://jcon-aps.dk/userfiles/file/70358100932.pdfIn PDF document text
    • http://besteva.com/upload/files/50612290226.pdfIn PDF document text
    • https://petala.gr/userfiles/file/mifidaxadaxogoxopu.pdfIn PDF document text
    • http://garmaclima.com/uploads/ckfinder/files/92856704774.pdfIn PDF document text
    • http://klawiatury-foliowe.pl/_data/file/tiwuj.pdfIn PDF document text
    • http://forumts.com/ckfinder/userfiles/files/43263996289.pdfIn PDF document text
    • https://www.psk.com.au/application/third_party/ckfinder/userfiles/files/69370404343.pdfIn PDF document text
    • http://krasneclanky.cz/uploads/dewutivaboxurijowod.pdfIn PDF document text
    • http://anoh.net/pds/userfiles/files/76077432860.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210909055257276227623.pdfIn PDF document text
    • https://globalybm.com/ckfinder/userfiles/files/1631193646.pdfIn PDF document text
    • http://ckrestaurantgroup.com/ckfinder/userfiles/files/novavi.pdfIn PDF document text
    • https://medsplus.us/admin/images/file/fifuvolafe.pdfIn PDF document text
    • http://www.dialog-seversk.ru/jsplugins/ckfinder/userfiles/files/nigipojafovexokuguzef.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_off0000d8bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8BC 11000 bytes
SHA-256: c524cf8bf960dc87ba89e92eddefee91012753a647d4fd9d7609237893a25d6d
font_01_sfnt_off0000f1ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1FF 19600 bytes
SHA-256: ec22b6ecb9b3105c449f07184ea77b95efb8e076819f032e6035d106109a2dcc
font_02_sfnt_off000124c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1