Malicious PDF — malware analysis report

Static analysis result for SHA-256 a76cabe0e953c5db…

MALICIOUS

PDF

77.7 KB Created: 2021-09-22 12:51:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 979e20789947f9983e721090d0b37d36 SHA-1: 04a50e8908eaf9d0f41023aa78857d00342200b0 SHA-256: a76cabe0e953c5dbc6e0ab578fa96f51c072a942929d4b62ad3740245793507f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous heuristics point to the PDF acting as a link farm, directing users to compromised CMS uploads and disposable hosting sites, suggesting a phishing or malware distribution scheme. The embedded URLs, such as 'https://ketchas.ru/uplcv?utm_term=excel+vba+pdf+download', are likely part of this lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://ketchas.ru/uplcv?utm_term=excel+vba+pdf+download
    • http://dienlanhhuubinh.com/upload/files/tizikugufokopin.pdf
    • http://parvazyab.net/basefile/api203/files/36431522878.pdf
    • http://turnwealthy.com/ckfinder/userfiles/files/febapakafirap.pdf
    • http://prasongp.com/file_media/file_image/file/16681961256.pdf
    • https://presstone.hu/userfiles/file/zewezatalavowemakuroj.pdf
    • http://jamones-luna.shopcloud.es/ckfinder/userfiles/files/13406399137.pdf
    • http://gemculture.com/userfiles/file/ruweruwebososev.pdf
    • http://champaigncursillo.com/userfiles/file/bikor.pdf
    • http://wangyiphk.com/userfiles/95386898612.pdf
    • https://giridhareye.org/ckfinder/userfiles/files/4764178149.pdf
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614176e23fa61---moralujobexukogevupokezes.pdf
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134490168253---kivaguraduzigunon.pdf
    • https://volnynaklad.cz/data/file/27134136481.pdf
    • https://villadorottya.hu/uploads/frontend/files/99317983746.pdf
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/50ebb1162110ffb09c4dbe76cae3857d/50955916968.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/161492add31ddd---84810271673.pdf
    • https://fancybox.pamlskovnik.cz/ckfinder/userfiles/files/vatibeguso.pdf
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/161326d418e50b---50337016481.pdf
    • http://www.autoservis-hubatka.cz/admin/upload/ww/file/72769540844.pdf
    • http://tovicetour.com/FileData/ckfinder/files/20210909_20D6682F36E9DEFC.pdf
    • https://ukmriptek.org/codeIgniter-hmvc/userfiles/files/17205345593.pdf
    • http://baovethanglongmb.com/upload/files/87316606945.pdf
    • http://riasztoszolnok.hu/admin/fck_upload/file/88550978386.pdf
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/7ce42866592d513f340fc33b86256abd/vuvofu.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_off0000cacd.bin
e9c84e9adf6ec70eff6c3b0233cfc0cf758fbb40d9e111b57c967dec95396fdf
pdf-font-stream PDF embedded font (sfnt) at offset 0xCACD 17944 bytes
font_01_sfnt_off0000f946.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF946 16792 bytes
font_02_sfnt_off0001115d.bin
cf717676ff019e84bcacfdec8deebd9ca2b2062027b9b09b26512ca093d9a64b
pdf-font-stream PDF embedded font (sfnt) at offset 0x1115D 10532 bytes