Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a1cd4328f8588a2…

MALICIOUS

PDF

93.3 KB Created: 2021-06-29 18:19:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9114a587a603e42e0dd7bc36eb30920e SHA-1: dd2ddd49429a578da4a8ab80c297c28475daaa2f SHA-256: 8a1cd4328f8588a2b4444dadac50dcbad9ad9cfde5914fcb6c6419f8ea3b3956
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised WordPress sites, suggesting an attempt to lure users to malicious or phishing content. The presence of multiple distinct hosts and the use of UTM parameters in one URL further support this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160777b10b06c2---pezinozisuva.pdf
    • https://sca-kc.org/scauserfiles/files/77312214102.pdf
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adbd0ea7a95---ragisudeja.pdf
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/bc70c1cb5c5d5a14a2f20b0f60b6845c/79778316078.pdf
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/bkb8tanvcuipagp5cp50bsfi36/20408215904.pdf
    • http://beiks.info/public/file/pasojiwibegepex.pdf
    • http://statsale.com/data/upload/ck/files/12060444670.pdf
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/1607e0f667c182---rakezatopatiko.pdf
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bcebd398db---leburejesoromozo.pdf
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/6c0e1ef090ba8fd4511431cfe2b6f54c/webolisuwofovuleputod.pdf
    • https://lotte-ppta.com/beta/assets/file/86779808231.pdf
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606dce2931568---93987294995.pdf
    • https://thegioidongphuc.net/ckfinder/userfiles/files/71835609977.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a0134aaa10---kinerafijutul.pdf
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/c0b847851c407cb4c836827efe1c96b1/88423335450.pdf
    • http://sarljarry.fr/userfiles/file/75462062407.pdf
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160915a89ef00b---7675461262.pdf
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/ef03896cab56971ed95bc1836aeeae81/65863740485.pdf
    • https://securityguardsupply.org/php/uploads/file/45464995802.pdf
    • http://gz-theoutfit.com/UploadFiles/FCKeditor/20210615213759.pdf
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/j000374b0ueqeneeb5v5esuj1f/tazaza.pdf
    • https://shoppingplanet.ro/ckfinder/userfiles/files/bigopikobupusevute.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=thangam+50+lottery+result
    • 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_off00010759.bin
2c9de3b5832324951f531be76a6ca5dc96b5845b8edd33a0730f81de2bbaa583
pdf-font-stream PDF embedded font (sfnt) at offset 0x10759 17444 bytes
font_01_sfnt_off00013551.bin
3ed478907d5d46b92bc07c534f38855b00d7f5addc2662a87a8b071d915ca860
pdf-font-stream PDF embedded font (sfnt) at offset 0x13551 10896 bytes
font_02_sfnt_off00014e77.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14E77 16792 bytes