Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8168174ad32d42f…

MALICIOUS

PDF

83.5 KB Created: 2021-09-01 14:26:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 02bd8b018d13ed33e58b23e66b5696e5 SHA-1: 77f631289508e4601232974d43cee2080a470ec5 SHA-256: a8168174ad32d42fcf357155ec3eab3d51cae512bcb1c40778e0b3974b31dfa3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file contains numerous links pointing to various websites, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple external URI heuristics and link farm indicators confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://archism.ru/uplcv?utm_term=pdf+the+compound+effect PDF link annotation
    • http://ferrocom-spb.ru/userfiles/files/suwosominubib.pdfIn PDF document text
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/c56b4ed8e995de7c933613afcf2670b4/17960554129.pdfIn PDF document text
    • http://rivebistro.net/ckfinder/userfiles/files/sazekevewuvirezudodimiwi.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/99488346717.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/dilonojebojunopijisexud.pdfIn PDF document text
    • https://seltec.io/images/uploads/files/95309664125.pdfIn PDF document text
    • https://termofriz.rs//files/fakenovifede.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160cc2dbde0ffe---61873914700.pdfIn PDF document text
    • http://ricarda-allegra.de/userfiles/file/vewugomofo.pdfIn PDF document text
    • http://eurekaelearning.com/upload/news/file/17143294791.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160ff988d73c17---87548434198.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086bf6299fad---tewufufozul.pdfIn PDF document text
    • http://kag.fr/userfiles/file/90423867112.pdfIn PDF document text
    • http://premiumdrinks.eu/userfiles/tozawasixizi.pdfIn PDF document text
    • http://mousike.it/img_ins/files/29935903999.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/415f135e82e760978916cacd30b22f38/31756887745.pdfIn PDF document text
    • http://tinavaron.com/ckfinder/userfiles/files/95943273056.pdfIn PDF document text
    • https://maxlinder.com/admin/assets/ckfinder/userfiles/files/90491381099.pdfIn PDF document text
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/1gtm0qie4uss3fcvsuv1vpnv7o/61454123467.pdfIn PDF document text
    • https://hw-power.com/uploads/ckfiles/files/60e941c717816.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/80053056662.pdfIn PDF document text
    • http://daiichigroup.net/uploads/news_file/35329237492.pdfIn PDF document text
    • http://baobianhkhang.com/upload/files/gowusobadajerubi.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160789c2176f13---14107106539.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2BF 10420 bytes
SHA-256: 588bca056f398f789ec3fce460b37494ac3207eeb1145a0546f946f47c723590
font_01_sfnt_off0000fa24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011236.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11236 17600 bytes
SHA-256: 0f6ec98be0e212f6880557bfcb8b588e149d8a0f83a05c1dedb0f2c87172143f