Malicious PDF — malware analysis report

Static analysis result for SHA-256 c63357f116592727…

MALICIOUS

PDF

74.9 KB Created: 2021-04-30 01:16:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 379589a373951f3e0c8a2c737ac916e7 SHA-1: f502ce5eeb742f0e201d165452379cf7b08c2f19 SHA-256: c63357f1165927272d0709bd3b76ee763252419464280617949d8349a215f78b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm pointing to numerous other PDF files hosted on compromised WordPress sites. This suggests an attempt to manipulate search engine results or distribute further malicious content. The ML classifier strongly indicated maliciousness, and the structure aligns with SEO spam or a distribution point for other malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://ccveg.org/wp-content/plugins/super-forms/uploads/php/files/n3fc36avl4s5hjlq6t8ves3244/fonofonekotaviva.pdf In PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16072f246eb1d9---vujuvulo.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160844633f0ddf---nasuterilujixemifa.pdfIn PDF document text
    • http://czdashan.cn/uploadfile/file/2021043005081973499.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160706aaf8b92e---nevetafafofisurerosi.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/ikj1g8ji67ate7fd9grt6mprh6/7473084670.pdfIn PDF document text
    • https://pensiuneavlasin.ro/wp-content/plugins/super-forms/uploads/php/files/65a1bo0q56l3o92qgpnpkpujra/42314074804.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/0ab6754b021ab893260b4a98bdbc5263/83444725203.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160749850750ff---28766083667.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/449621f17fa1921a53bd851f84ed926c/50003587136.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073e1a8e22d1---22093064130.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/574ab6d7572d3d6e117a6653397b7719/87174954996.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/16086a7afdbe05---jinovexez.pdfIn PDF document text
    • https://mziagroup.com/wp-content/plugins/super-forms/uploads/php/files/f0um7gq4h2aqm07nril4fn5b8e/nuwepamubisigugimewem.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607207e685d9b---powovesojakudopuja.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/f87c8f34c454fd52deb6362fadb2c0f5/temabozeburutijevafakod.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=importance+of+effective+business+communication+pdfPDF link annotation
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA77 5408 bytes
SHA-256: 24db04df72b0ccd6df3ac88a160069e97a5c2ea56a95d4e9c9e98aba5e812f53
font_01_sfnt_off0000fcc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCC3 9940 bytes
SHA-256: 4dfc7feb5207697049e4d0323c2660a151b1b8b48c2cf69f913162be310ffa40