Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cf704c875cdce83…

MALICIOUS

PDF

82.2 KB Created: 2021-09-18 11:04:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9fe4e44d8781e20dd570cf6c5bd6ffeb SHA-1: 3efd2f2e9a3ece7afbe7112d5df3f7b08101739c SHA-256: 8cf704c875cdce8379e711d4c123ceab4c5a9b73286fbb39fba661f47375044b
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains a link farm pointing to multiple compromised WordPress sites and disposable domains, suggesting an attempt to lure users to malicious content. The presence of embedded URLs and the nature of the heuristics indicate a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://laborke.ru/uplcv?utm_term=android+app+development+final+year+project
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/5fb2d76e45a8be3175bd0f9cc14ac39c/84806852014.pdf
    • http://diakmelo.hu/ckfinder/userfiles/files/koderuvogeba.pdf
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/guwuvolofizizowaxatemaf.pdf
    • http://raczpalinka.hu/userfiles/file/resosoro.pdf
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614427282487f---23260976962.pdf
    • http://crestviewshopping.abwingsmd.com/uploads/files/kitivosofoga.pdf
    • http://shesob.com/file/files/vemisolo.pdf
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/t85k07ib15q17iggr2qrd59r74/supawelidajokaxawubuvop.pdf
    • https://insolite.lu/img/userfiles/files/jexuge.pdf
    • http://baharev76.ru/userfiles/file/vilowakazovem.pdf
    • http://trineckevzdelavani.cz/webpagebuilder/ckfinder/userfiles/files/47084667513.pdf
    • https://indirimlipin.com/calisma2/files/uploads/91266971058.pdf
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/b8b536051fe75cd6b16493ddc1fd9de3/zapovamejobi.pdf
    • http://xn--80ahcjevtqq.xn--p1ai/ckfinder/userfiles/files/kizaraberemowuw.pdf
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141d2d54e398---21606900797.pdf
    • https://gastrotest.co/ckfinder/userfiles/files/sisupisetuturaxolarut.pdf
    • https://raljob.com/userfiles/file/6646838611.pdf
    • http://zs-oilfieldequip.ru/d/files/11642352788.pdf
    • http://adamslakeband.org/userfiles/file/52565287793.pdf
    • https://postele-z-masivu.sk/ckfinder/userfiles/files/41994844358.pdf
    • http://drivescuolaguida.it/userfiles/files/10725476142.pdf
    • http://sllight.ru/design/img/upload/file/betifoxuxag.pdf
    • https://huuphongplastic.vn/uploads/images/files/konuba.pdf
    • https://cam-ceeds.org/ckfinder/userfiles/files/15095772967.pdf
    • http://geredekombiservisi.com/userfiles/file/12142810327.pdf
    • https://shindah.com/images/ckeditor_img/files/16554655553.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_off0000db2e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB2E 16792 bytes
font_01_sfnt_off0000f340.bin
fcf1fb1fc77c03e4d75dfefc11798d5395807a70b613434d19dfd4e30fcc942f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF340 17824 bytes
font_02_sfnt_off00012162.bin
7de2a76ff9312a8887f40842812a98af5b55afe36d1c5db4676b36e43bef1344
pdf-font-stream PDF embedded font (sfnt) at offset 0x12162 10904 bytes