Malicious PDF — malware analysis report

Static analysis result for SHA-256 88ca6358d29118a4…

MALICIOUS

PDF

81.5 KB Created: 2021-09-13 22:28:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: af8436c2500d0a60b33a8c8c4fe98473 SHA-1: 0742ac2c5f13ec712808f1f2b307589d60726824 SHA-256: 88ca6358d29118a434a72f9f77674b08063e9df5b39cdce15eb2695b51a42011
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS uploads and disposable hosting, indicating a link farm designed to lure users to external sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16136511c31ee0---dawavokulalu.pdf
    • http://covina.crazyrockinsushi.com/uploads/files/sotazag.pdf
    • https://asharfilalkulfi.com/ckfinder/userfiles/files/91855916189.pdf
    • https://medpressa.ru/files/file/lewazabotiwavurifigubu.pdf
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/161327ec76b543---matezuxewusav.pdf
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/3e177697edc725fd887cdf69fc39ad11/zikosavasi.pdf
    • http://1-champagne.com/blog_images/blog_/file/majozalufibe.pdf
    • http://alfavs.eu/userfiles/file/45567185849.pdf
    • http://unseretochter.ch/images/file/kikuputedimaxev.pdf
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16133f48c9fc17---47365136472.pdf
    • http://www.ecostroyservis.ru/File/vewojejodonikebipi.pdf
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137700c0a3ad---76103111398.pdf
    • https://directorvincentchow.com/fck_filemanager_upload/file/86726816314.pdf
    • http://floramarble.com/uploads/kufawodaw.pdf
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/b6d612773e3bc64ba73ff3ed63c67f65/21281610358.pdf
    • https://aksukartela.com/images_upload/files/zevujonuvetupebejizudaxum.pdf
    • http://mariopresto.pl/userfiles/file/savigibedetalisimot.pdf
    • http://rotarybrescello.it/userfiles/files/29082772089.pdf
    • https://sjamsul-hidajat.id/ck_uploads/uploads/files/saziwa.pdf
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/ba13d6be22f4dc7fc91f348e23792906/momevulezesaxixopekox.pdf
    • http://dbexpertise.fr/catalogue_dynamique/file/62222398442.pdf
    • http://old.bgk-meshkova.com/ckeditor/ckfinder/userfiles/files/55834351045.pdf
    • https://architektor.ru/uploads/file/wikemosoxarej.pdf
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/fb7bf4d0f45ead1edaf3153a9a296221/xofeponanowilunogoro.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=why+is+my+android+memory+so+full
    • 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_off0000d850.bin
a123ff45d41a6eb0eb19d98bf48a651890bc6981adf103fe7d2eab46d57b1971
pdf-font-stream PDF embedded font (sfnt) at offset 0xD850 10728 bytes
font_01_sfnt_off0000f0b7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B7 16792 bytes
font_02_sfnt_off000108c9.bin
f96a7b5ce51b1b49db889b97dd2c55fe3822dbb7e50b7b7858c00112518cccda
pdf-font-stream PDF embedded font (sfnt) at offset 0x108C9 18132 bytes