Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7373cd3fcf3b61c…

MALICIOUS

PDF

72.1 KB Created: 2021-07-05 05:16:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7379ae414adf8fe38619f4b9098ad91d SHA-1: 23f64767c4f9cc654d711b913e9f5e60af36ea85 SHA-256: c7373cd3fcf3b61c6b9fae849feb423e0d3ebf816f8cb899d73c15713281bb64
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress upload locations and disposable hosting sites. The embedded URLs, such as 'https://irlanc.ru/uplcv?utm_term=lyrics+dont+fence+me+in', likely serve as lures for further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://irlanc.ru/uplcv?utm_term=lyrics+dont+fence+me+in
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085201dc4197---mulofupezikopejurotelepud.pdf
    • https://ozmutludokum.com/userfiles/file/vuxadab.pdf
    • https://brianhigbielaw.com/UserFiles/file/42839037642.pdf
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077e9a6c5c8f---rofatufagibulidinu.pdf
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/g8eve95f986er991o61bj1lpt5/gafefun.pdf
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088c379cc477---nebum.pdf
    • http://pokewaveanaheim.com/uploads/files/nufamuginivivirilul.pdf
    • http://samurairamenbar.com/uploads/files/wenokimoxuwu.pdf
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/16087ef9a84703---67913437926.pdf
    • http://allg-gyn.ch/userfiles/file/78962534235.pdf
    • http://monroehighbeachreunion.com/clients/8/88/88bd109b8fc96949fe6caf7698e88fda/File/15158029613.pdf
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bdcf2d08926---velobusavexazinokuriwas.pdf
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/f7ec720b1ef13d88e4cf9187f756fa05/5440114454.pdf
    • https://pointsourcegroup.com/wp-content/plugins/super-forms/uploads/php/files/a4553690503bebb1c66af6e3490debc5/lepavupifa.pdf
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/895ed89c9106fd582545c673c33e99ac/8370889504.pdf
    • https://ipic.vn/userfiles/file/lokekodagamusekijujager.pdf
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/mdi2b26ls89j2ijupq3hprhcq6/56273389582.pdf
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/16075eb003c6b8---97475489812.pdf
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/a298b46254fdc9e77f430440619d8a16/dijipunilakogelisok.pdf
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/7catadr868fqd7mgq7j9jlfp2o/58892613828.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d5b92d0465---21776172229.pdf
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd692082762---31731371132.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_off0000bb9c.bin
466f8e225035273de2b95001c3aa49b8e3b91a86bb5f5fb7e4d17bb09557577d
pdf-font-stream PDF embedded font (sfnt) at offset 0xBB9C 10500 bytes
font_01_sfnt_off0000d37e.bin
b99e7b6684b09bffa7eeacc70fc77419957263c35caad834643c26560d71f7d3
pdf-font-stream PDF embedded font (sfnt) at offset 0xD37E 15420 bytes
font_02_sfnt_off0000fb66.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB66 16792 bytes