Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5803c91ed822f54…

MALICIOUS

PDF

89.6 KB Created: 2021-06-26 09:25:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 87d40123754b0e792df8ac4c2904811d SHA-1: 2127d735d994d7fda360e2c2398fb24ccade8a01 SHA-256: d5803c91ed822f5407e5323b8a9cccfbe1fb1a950e6b5574dbca680ed7896731
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress sites and disposable hosting, likely to distribute further malicious content or phish for credentials. The embedded URLs and the nature of the link farm suggest an attempt to exploit users through deceptive links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://coretry.ru/uplcv?utm_term=once+upon+a+time+in+mumbaai+movie+songs
    • https://www.deuba.info/wp-content/plugins/super-forms/uploads/php/files/bo4ao7fip8q2v05iv8gitf8fbe/20922027301.pdf
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160b2c5367cd32---79301734504.pdf
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160949f14ab090---69225391122.pdf
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d19e651fd5---34953626734.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160714196337f1---tusogokuvelo.pdf
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b817c7238ef---gateveximipobawixas.pdf
    • http://renovator.cz/files/file/46715954584.pdf
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/5fcc5c271c84c056f1947f84deb0de7d/veroveronaw.pdf
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/487f00bea3a8e73205ebba9d7bfaf905/wamotunoluvaf.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a8b0f96eb05---74721604219.pdf
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609da3bdbed4e---24350440157.pdf
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160924faf399c1---22863787354.pdf
    • http://gayaarchi.com/userfiles/file/20210518204743.pdf
    • https://lawina-radom.pl/files/file/pepafi.pdf
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8fa84822c---pivowanoxuwobolipafom.pdf
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/44ea15f36fa31a89d2e218b062fb8fef/60321109707.pdf
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/laefbr8mui76hq173g8uvta7df/40418309467.pdf
    • https://office-agglo-larochelle.fr/userfiles/file/55735864865.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/a6832e3c40b43e9deb9fcc03e9889191/tolorunewopo.pdf
    • http://yuha.be/_files/file/raxerimubep.pdf
    • http://bhttourist.com/upload/fckimagesfile/divun.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609244f03dde2---kagabopi.pdf
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/ebafb9c150f12f9cc6e700d266a436ff/jokozowa.pdf
    • https://legacydockandmarine.com/wp-content/plugins/super-forms/uploads/php/files/2aba7e735d2ead79919baa7f2fa4d427/38982132386.pdf
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609119bdd05ed---51991974368.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_off0000fb58.bin
a341324773d185e97b0085aa86921375f6510efac407664dec6cbb060473620b
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB58 10900 bytes
font_01_sfnt_off00011477.bin
ea30f3387eec40c66fed3c0d87e28c771c9eb2330125da363587a872390de8ac
pdf-font-stream PDF embedded font (sfnt) at offset 0x11477 17184 bytes
font_02_sfnt_off000140bd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x140BD 16792 bytes