Malicious PDF — malware analysis report

Static analysis result for SHA-256 f621d79ee636cdf8…

MALICIOUS

PDF

83.4 KB Created: 2021-04-27 20:51:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 1b43370060c93e14465d66c38c15e709 SHA-1: 20184373b9bc8a3df15185614cdc1578f94a8ade SHA-256: f621d79ee636cdf8eb7a33429fb64e789a15c85bc82c73fbe0e328f72a18248c
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The presence of external URIs and link farms on disposable hosting further supports a phishing or redirection attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607df842aefb0---mozezaf.pdf In PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070fdb1b294c---wigojirib.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/a777e5f9a660718e0e04f5eff7f7856b/76479867621.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086a2059017c---juwadikipijefifixabigari.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/009bb2a95008cfc95b132ba255457037/64221217407.pdfIn PDF document text
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/bf89a1372222940494d975d7eb406146/nalijemogozuluguv.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/f76fdb410c0750ffc3e96cb00c7e5900/28936218250.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/a909527c7634a697b60c4264dc645908/doguxurewawawomuse.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0c9a3a06c---29614174526.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/fillhuj44tdmsn1fv84d4rs7n6/41401603667.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f59e8dc257---lirabowazuxinafetegapep.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/072f025dc36f0810bf95bb73725aa52a/90055867574.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/f96e0c80866aa3ae7b9168e722dfc763/lunevida.pdfIn PDF document text
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/8db7a2f33d86557ecfc3dde66ece111c/39916670454.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607603ed69a13---38815065807.pdfIn PDF document text
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/f976844de168b70f4ea135e371a56ebc/1862846516.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16076476716d06---73331419849.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/BkSY9tpko7c/uplcv?utm_term=the+goldmark+report+in+1923+recommended+thatPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f7b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B0 4524 bytes
SHA-256: 8c64e09e6818e00018a78e55c15ebe80af48a937fce0996f60a0bf1040368e9c
font_01_sfnt_off00010757.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10757 5828 bytes
SHA-256: f11dccd242e9eee35c6ef6d4eb1baa5b224a406d8740bae808a5096ed0abd3b1
font_02_sfnt_off00011afe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AFE 10656 bytes
SHA-256: b9ff7726ed17f43de732c4579fcbbed65b79ec34d52b2807f2eac11abf3964ec