Malicious PDF — malware analysis report

Static analysis result for SHA-256 4db51e910d8c1c34…

MALICIOUS

PDF

84.4 KB Created: 2021-09-20 08:07:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 495d8bcc09f686c9fb0e5558f3969649 SHA-1: 5baa5c5d918c9af2ae735f3e535acc1744c7dda7 SHA-256: 4db51e910d8c1c3489d7fa953ae26bd5c86261d445ca13087e5cc128674e8eab
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are hosted on compromised CMS platforms or disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to trick users into downloading further malicious content under the guise of a firmware update.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://catamma.ru/uplcv?utm_term=download+firmware+samsung+galaxy+fame+s6810+indonesia PDF link annotation
    • http://www.enredmail.com/templates/files/idCliente_/file/buzubegulogajije.pdfIn PDF document text
    • https://ist-lb1.istanajp.com/contents/files/1687591156.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614255fde05b1---moxoxiwamomaxob.pdfIn PDF document text
    • http://studiocariola.com/userfiles/files/xajukifajitetixegafifipin.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f9d667b54e---54686852192.pdfIn PDF document text
    • https://windscrm.net/files/file/renodirif.pdfIn PDF document text
    • http://ideviceplus.be/app/webroot/files/userfiles/files/78886593390.pdfIn PDF document text
    • http://joeun-it.com/userData/board/file/xolujinawak.pdfIn PDF document text
    • http://hotspot-usa.com/js/upload/files/xepewajipogabanita.pdfIn PDF document text
    • http://edu-family72.ru/content/images/uploads/file/98114550215.pdfIn PDF document text
    • http://hyunshin.net/userfiles/file/vazikobepudanasi.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613a3e5896551---51071373478.pdfIn PDF document text
    • http://poliinc.com/upload/files/81520565554.pdfIn PDF document text
    • http://athaj2.specialty-match.com/upload/files/27232950731.pdfIn PDF document text
    • http://sapientgenerator.ru/files/userfiles/files/55660717648.pdfIn PDF document text
    • http://area100impianti.it/userfiles/files/sinegazofofajokifexidoder.pdfIn PDF document text
    • http://cbestdesign.com/ckfinder/images_store/files/86827187906.pdfIn PDF document text
    • https://osakaav.com/userfiles/files/36189992568.pdfIn PDF document text
    • http://syntrend.critical.tw/upload/files/tupuxitu.pdfIn PDF document text
    • https://tckontrola.hr/files/11899862161.pdfIn PDF document text
    • https://bunyaminerdemir.com/resimler/files/73281109633.pdfIn PDF document text
    • https://ises.ca/phpsites/vertical_living/uploads/file/xisuj.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_off0000e212.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE212 11552 bytes
SHA-256: 09840809218e667023908326397694008448cead74239c0e8c0e036b98784975
font_01_sfnt_off0000fd5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD5E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011570.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11570 17696 bytes
SHA-256: d2c0a5486ccb2cd3762aef91ac8d03682796ffd576d21b43d6c771edfa6ba15e