Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4485508f99f7636…

MALICIOUS

PDF

83.9 KB Created: 2021-08-03 02:19:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c8ea106d34c8875e1815b8399fad5c9e SHA-1: 3c55458abc032f7c94e136be40f73ce294b11559 SHA-256: b4485508f99f76365dbab17f999c58e61a69f4bbe924c929b340766162261a0b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 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.
  • 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 http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161026acc26cc7---nasajutedolizenorog.pdf
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/l6bc3e2v8b5jc3sct61id0gn0j/sesokozukorezezemu.pdf
    • http://mazdooradda.com/userfiles/file/diwifafikixeveturezedi.pdf
    • http://doradcyprawni.com/images/pliki/janafodosemebobimavesi.pdf
    • https://ceral.pl/ceral/pliki/file/9839781054.pdf
    • http://softtox.com/new/userfiles/file/kuxudazolosadekekazupi.pdf
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607ca13c50cbc---zumixumezuzi.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0ca6735cd0---74385020117.pdf
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073ed54aa86d---vanawijog.pdf
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071ba9f96c6d---96849663332.pdf
    • http://chiangmaicharmingtravel.com/ckfinder/userfiles/files/70075962999.pdf
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/62800719536.pdf
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16080991052dcd---48077528199.pdf
    • http://accessprecision.com/userfiles/file/gibiwalo.pdf
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609aa0a98b104---retotipajadug.pdf
    • https://rent-1.es/ckfinder/userfiles/files/44804085468.pdf
    • http://benthanhsgfarm.com/images/uploads/files/61130407095.pdf
    • http://beijingxinzhi.com/userfiles/file/20210801194709_1456703170.pdf
    • https://travelinnsuites.com/nbloom/fckuploads/file/nunutixigobud.pdf
    • http://petswithlove.com/cvsprojects/SSK/Source/2.0.0/images/files/18300100743.pdf
    • https://triosms.com/userfiles/file/21645217903.pdf
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adb9ca83a3a---wugujukopoxenowe.pdf
    • https://agrimal.pl/userfiles/file/6504816670.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=place+value+and+value+of+decimals+worksheets
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e3f7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F7 16792 bytes
font_01_sfnt_off0000fc0e.bin
6d9eb94f300dd33bc76007d56c033c18f3339aeb67864e26e27bca024cd5ca88
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC0E 11084 bytes
font_02_sfnt_off000115cb.bin
7e07856210087e2f85f2af59f2e9b59c78d155103e31013894b17819dba286cd
pdf-font-stream PDF embedded font (sfnt) at offset 0x115CB 16400 bytes