Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8af7bcb7ac3bccc…

MALICIOUS

PDF

87.1 KB Created: 2021-08-01 01:26:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5a0a881ace37de257e17ecce25148017 SHA-1: 8ab23f3d7f55e40b2f5e7c9ee1b58adcab792b59 SHA-256: c8af7bcb7ac3bcccd5ff02998d5f2bec569949f91de58d81c1c8a1cf6ca67b25
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm pointing to multiple compromised websites, a common technique for phishing or distributing further malware. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically highlights this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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 https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/dff0a38849c6ac73a542a42c2bfa913c/1255869294.pdf
    • http://4998horo.gmmwireless.com/contents/files/56964843472.pdf
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5b47e1ff7e---82573952848.pdf
    • http://autoset66.ru/admin/ckfinder/userfiles/files/xagapavafeligibomateb.pdf
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160989a77e5e16---ralafejotix.pdf
    • http://eaas-journal.org/survey/userfiles/files/pufupinekurelinotajazatut.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160d9fad7beaeb---nakadetofotuzogo.pdf
    • http://hainescentreasia.com/images/file/7718668825.pdf
    • http://komputerzagrosze.pl/userfiles/file/jirijexem.pdf
    • https://juvelyrikoscentras.lt/Files/file/14852511812.pdf
    • http://atenngo.com/admin/sites/site/documents/15001680764.pdf
    • http://frangarcia.eu/upload/file/16500211089.pdf
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/df5060615b086e10fce86fc2dc917e98/9193992003.pdf
    • http://studiopignotti.it/userfiles/files/37566896254.pdf
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/a10a3de2919ff84764be179561c53670/kodusisilojupibo.pdf
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/52753105dac376cc88d487979447a016/zapugepaporoduwimiz.pdf
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160f4452278cb8---66772283903.pdf
    • https://tripleccompanies.com/wp-content/plugins/super-forms/uploads/php/files/9b125f33e4487a260e9ed71fe9e688c1/xajeruno.pdf
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/1539900c9c65680422e9bc49d3d3ae19/29470198726.pdf
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba3f4e6dac2---72144188971.pdf
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/dduhd9lb3pgh364a3v0ndocbm6/zorodepezojivifikubegote.pdf
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b27057c3f75---15205059291.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+set+up+bluetooth+on+jvc+car+stereo
    • 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_off0000f02f.bin
f436e739691735062575f71908cdf6257deba8bb453c8c54fb0eefdb7cb50f00
pdf-font-stream PDF embedded font (sfnt) at offset 0xF02F 16512 bytes
font_01_sfnt_off00011ad3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AD3 16792 bytes
font_02_sfnt_off000132ea.bin
7f7c667281ff54fdb4be1e2ba4ee2bc0d3961f7828a603abcbf1549d7f6c646a
pdf-font-stream PDF embedded font (sfnt) at offset 0x132EA 10892 bytes