Malicious PDF — malware analysis report

Static analysis result for SHA-256 f21c76affc2b6d77…

MALICIOUS

PDF

76.6 KB Created: 2021-07-03 02:19:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cf2b358884b41cfb963995c83978a474 SHA-1: f7e4aa729d54915daf8f686c258d933781a16633 SHA-256: f21c76affc2b6d77677834e8fc1c6bfb709568548d6d6a701608ba9363e4e3db
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress upload directories and other potentially malicious sites. The primary purpose appears to be directing users to external resources, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 https://drafthe.ru/uplcv?utm_term=wart+in+mouth+child
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160908da66420b---darirasezakukopekepuganob.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160b0345f59f70---lawogutomi.pdf
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094055116560---vobekowojadu.pdf
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/ja3koq2hv24lbmv1k62kl96hu2/68029345577.pdf
    • https://bodwellassociates.com/wp-content/plugins/super-forms/uploads/php/files/14004b0c8ad576e8d13efa757cf146d8/38844825290.pdf
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/d0087a3e395c87d7d91332cc824bde76/75209751648.pdf
    • https://parklanehotel.asia/userfiles/file/tukuxum.pdf
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607eaa355bccf---famofirejasulonobaso.pdf
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d20479b4c3---sevawasetove.pdf
    • http://fructusartis.com/i/File/78323768664.pdf
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607844f498597---kimop.pdf
    • http://huiking.cn/uploads/file/190234002934.pdf
    • http://vom-ragnaroek.de/uploads/file/98668777284.pdf
    • http://holidayservicemarsala.it/userfiles/files/kaxitafilad.pdf
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/sscfrl8oj0kh14mpnfuj7c3tpl/mozazipirosukonorepu.pdf
    • https://pablohernandes.com/wp-content/plugins/super-forms/uploads/php/files/b45a233a2f92971418b8ee7714733a52/logagebodufutenedu.pdf
    • https://comfortinnbarrie.com/phpsites/vertical_living/uploads/file/75559656366.pdf
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/6p6shp361t16g49s1d0g73l174/nitaz.pdf
    • http://hesexpo.com/img/editor/image/file/fimokesabewizibejazuvof.pdf
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160725c3e9a440---vadategu.pdf
    • https://alice-immo.com/userfiles/file/doluzebinukopekufo.pdf
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/9a2f8e3ca57e8f1f8f44c84f0aa0b1b3/perepujubijiregi.pdf
    • https://pointvirgule.ca/upload/editor/file/40772412293.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_off0000ca76.bin
cda5efa5b7c3b0801c14e2b90a5e0134fc1b8c11438655060d24ddfeb4e1c541
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA76 10428 bytes
font_01_sfnt_off0000e1db.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1DB 16792 bytes
font_02_sfnt_off0000f9ed.bin
5bb34d14d78b3eaa51c011f015bfc91e9925cb551cedf11f64c769737a6179f5
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9ED 16712 bytes