Malicious PDF — malware analysis report

Static analysis result for SHA-256 27c7a3537e81c522…

MALICIOUS

PDF

70.4 KB Created: 2021-04-27 19:50:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: 6c20a05efd4291f6a1b59dcb5d2aa255 SHA-1: 4f27487c480cb76feae3e33248a0736bd7b591ac SHA-256: 27c7a3537e81c52254641c0eb3b0d9a0f0c9b606bbaa9171216b4c1f2fd893ab
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 ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised WordPress upload directories, likely serving as a distribution point for further malicious content. The presence of multiple distinct hosts and the use of disposable hosting suggest an attempt to evade detection and maintain operational resilience.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/117b0cca3989087cd6ee388e97a07d23/dafigibunepivevutarututub.pdf In PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608364c9cd1c2---kafaritetexusipatuginar.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/889f0dfa3584bfb36d0dc30e9f44ed38/29152393455.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607428422f24c---xelatumiximimep.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/6c565db890f9c8b1873138914326d8fe/sojatixiwev.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160773920dd790---74756480473.pdfIn PDF document text
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/7892f6e8ed80e308c19bd3e9169377af/fenebozomogaxajewuge.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608108a27bf70---fajozefobazat.pdfIn PDF document text
    • https://flexrocksrollovers.com/wp-content/plugins/super-forms/uploads/php/files/evqbgukgospkjo920c3ipq3gfa/45407485672.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607306b4c9202---vesugekukapevunelixa.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/bc2c2757098654b5d2e8560d15147e0e/zadedogopofivujedoz.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/1fa4894c73e04eac2ab57956e02b55dc/26593108733.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16080a92c420db---wesimamufojogiduweziroxu.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160749f5462221---10792984470.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/682ff251fb89fb08751a1cbd1a221596/gezeveletopisosi.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160805c0df26d6---36795524009.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/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=automate+android+carPDF link annotation
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000de0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE0B 4864 bytes
SHA-256: ef96385433d70144d8cc9030c66acc8b4f661e96ccd93c58f1a8ed58921b162d
font_01_sfnt_off0000ee75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE75 10752 bytes
SHA-256: 973131f674e40f989d07cdc27102c0e7aed164d439f281bb3b767a7d3bde6bc4