Malicious PDF — malware analysis report

Static analysis result for SHA-256 88abc6a41ac970c9…

MALICIOUS

PDF

78.9 KB Created: 2021-09-04 12:15:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ae5193d7f128f82b4e09c1521ca2b484 SHA-1: 254b762d5f0bc07aa3a63c492edc07961a8df2cf SHA-256: 88abc6a41ac970c9187ea33bbae1ad1ce4d3ca8b47d21d33d657a8793c76c69f
156 Risk Score

Malware Insights

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

The file is identified as a malicious PDF by multiple heuristics and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised websites, likely intended to lure users into downloading further malware or engaging in phishing activities. The presence of external URIs and link farms on disposable hosting indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://medvor.ru/uplcv?utm_term=exposure+diablo+mk10+manual
    • https://living-stone.lu/userfiles/files/78880654929.pdf
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607d98b3750f1---84075492476.pdf
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dae459e53f---fofunimusubepasesidod.pdf
    • http://jnnycc.org/userfiles/file/pitezamoli.pdf
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/c4f4823f19394708a6fe639e9f8704e0/rupetixixuxa.pdf
    • https://cmflower-kkc.com/ckfinder/userfiles/files/pojari.pdf
    • http://1careglobal.com/upload/files/pilezetuzikofoxupubotusu.pdf
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/88726144019.pdf
    • https://soudurelauziere.ca/upload/editor/file/48794822099.pdf
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/3bd21f2964c83fda77bc7b36a90b3f5d/52262524897.pdf
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/8d77548df2b04cbdaf0927a72cb8198e/55641738039.pdf
    • http://xycrusher.com/d/files/9477251362.pdf
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/f79f700717fc5738dba8952be47dfce4/99718049227.pdf
    • http://esebtekstil.com/resimler/files/xebaf.pdf
    • http://xn----0tbbbfo0f.xn--p1ai/userfiles/file/82789850553.pdf
    • http://shuswapladystriders.ca/userfiles/file/46226108050.pdf
    • https://isosklo.cz./uploads/75035606268.pdf
    • http://rogersdesignhouse.com/uploads/files/22217552019.pdf
    • http://kadh.kr/bobod/upload/file/vimilekikukexixonikux.pdf
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/ce9dca6dd1eefe94c2c2ab6052d36f29/18309261421.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c26bb731f75---67602927865.pdf
    • http://theurbanbazzaar.com/userfiles/file/58970699312.pdf
    • http://autoshiftbid.com/fckeditor/userfiles/file/28449459132.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_off0000bfa0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBFA0 16792 bytes
font_01_sfnt_off0000d7b7.bin
c81e1d138d2b2f7b2e734be0144afabe6a3ae8b644d8f5a772766ff533029170
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B7 11048 bytes
font_02_sfnt_off0000f11f.bin
4d1a6f7ae7998f0d4b7b841a7f256884755acbec1fe308735af248bf39342b61
pdf-font-stream PDF embedded font (sfnt) at offset 0xF11F 23352 bytes