Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cd8aa16d6f3cfde…

MALICIOUS

PDF

89.9 KB Created: 2021-06-29 23:11:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 920231371c27d6b4f4389c7daf7924a5 SHA-1: ec1157f567a55606d67d153d8a695b04194e4823 SHA-256: 4cd8aa16d6f3cfde6af756f89191ee4fb93202e95946bcb685790715de25ca47
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites and disposable domains, likely for phishing or malware distribution. No scripts were extracted, but the presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest a phishing or credential harvesting campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://crysiq.ru/uplcv?utm_term=what+rising+action+mean
    • http://apcmagon.com/userfiles/59652303998.pdf
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/8138e172e2f11d0ef71897dc1fd6b9d8/podenarilejajosejibulef.pdf
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/4bdbd70140203a884032db8cb7efa5db/xofix.pdf
    • http://blesk-stroy.ru/userfiles/files/21031986240.pdf
    • http://avonsteel.com/UserFiles/file/51753855423.pdf
    • http://banglatalkies.com/dynamic-images/cms/file/ligoxewowewun.pdf
    • http://fusheng-vietnam.vn/admin/webroot/upload/image/files/69606657002.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607c317aec168---zotubidinenu.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609b4fb96969b---62315900360.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160d1f589c204a---95527557154.pdf
    • http://martom24.pl/martom/userfiles/file/28743212975.pdf
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cde1472660e---72226104171.pdf
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/f82f4cf70f0d2d86047971940cc491bb/54489183186.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b0946e53647---bidabe.pdf
    • https://ildiko-szepsegszalon.hu/userfiles/file/58029736677.pdf
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16075fae7a60bb---80338352116.pdf
    • https://ludifrance.fr/userfiles/file/13224836910.pdf
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/92b8468adbfbdd89e8399be1bd289920/bumifekesu.pdf
    • http://dent-pro.cz/pic/file/sejidoxizemelizif.pdf
    • http://graylegalservices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/50760804664.pdf
    • http://malbreil.com/userfiles/file/630422828.pdf
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/ff435c268848ee28552f12f3b935a6e7/tizenubavolirikijuzeg.pdf
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b560a2d958d---fidofirijaj.pdf
    • http://przedszkolenisko.pl/userfiles/file/94072036865.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c296dfa93c2---99441296713.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073a89faea13---25545569221.pdf
    • 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_off0000f8ac.bin
acb3d6366cf6b1214a0642ef570a07b41e8af3c9484b9dcf8c6d0ede80ef55e0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8AC 19080 bytes
font_01_sfnt_off000129e7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x129E7 16792 bytes
font_02_sfnt_off000141fe.bin
6a8596fb16de5127afdf08bebd086907e1af115c973029023c419f6150cc8c6b
pdf-font-stream PDF embedded font (sfnt) at offset 0x141FE 10624 bytes