Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9f6f21480873f48…

MALICIOUS

PDF

87.7 KB Created: 2021-08-24 23:59:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6e5c283a4edd0714b08007e64f31ecc3 SHA-1: 9927a7416faf1d02370b74800074dc67f9c6c338 SHA-256: b9f6f21480873f488ac40a3175fe19170bc8ee50fee9b38a3855a275f65dec6f
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, and contains numerous links to compromised WordPress sites. These links are likely part of a link farm designed to redirect users to malicious content or phishing pages. No scripts were extracted, but the presence of external links suggests an attempt to download or redirect to a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9fb25ad791---18829918408.pdf
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/nukobuw.pdf
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/efh62u49tkrh6892b6hfvu48d2/tazudo.pdf
    • http://dep14kirov.ru/userfiles/file/putazetazuzegil.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/cefc3ab50777549010e5fcd3ae6e62cc/4649127952.pdf
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/mutijuvajavebeweki.pdf
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcfd47d12da---welikuwofikonaxupeteseze.pdf
    • https://foodsafebox.com/ckfinder/userfiles/files/pezenufeserigib.pdf
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/53921702730.pdf
    • https://happycolaborativo.com/uploads/files/78824957150.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160942cc0621f2---87108751731.pdf
    • http://soldresold.com/Shradhdha-Mehra/soldresold/final/ckeditorimage/files/rafetitinuzotalepijap.pdf
    • https://nhathuydesign.com/wp-content/plugins/super-forms/uploads/php/files/qh7ci7r7a4jnff8t1dbaiarl5j/26261262970.pdf
    • https://airshow-bg.com/file/57245968909.pdf
    • https://linhngapt.vn/upload/files/zimaxijobodipiseropesebi.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/161183e457bfe2---73400412114.pdf
    • http://builderall.info/userfiles/file/kobejetelunelisavalak.pdf
    • https://acgroupenterprise.com/userfiles/file/waxosavinejofuz.pdf
    • https://ntct.dz/ckfinder/userfiles/files/wunodipaluki.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/r8n7nr711rb7i2q5tskrov4mh5/guzawabu.pdf
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609e13756eef3---38848678275.pdf
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/ff53d6223bd66ed808aaea826e371ecb/tulupurig.pdf
    • http://grossfamilyreunion.com/clients/0/00/00c8ca1d7e0432e0ca4c178cf0a97985/File/ruviwivinetekuliz.pdf
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab954feff96---memuwunegoketidi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=street+lighting+is+an+example+of+a
    • 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_off0000eea2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEA2 16792 bytes
font_01_sfnt_off000106b4.bin
7d23a23e8580aca0d9abd085748dfec3952c034546d57bcbc95bc8e73a7b4056
pdf-font-stream PDF embedded font (sfnt) at offset 0x106B4 18496 bytes
font_02_sfnt_off00013721.bin
e3ec1b8a3e1ae0e6dae191c9fcac4d92c2a736ccd9183f12d7de66f570f3f8b3
pdf-font-stream PDF embedded font (sfnt) at offset 0x13721 10984 bytes