Malicious PDF — malware analysis report

Static analysis result for SHA-256 6991fcf002b4c91c…

MALICIOUS

PDF

86.4 KB Created: 2021-06-25 15:41:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 057ee46de3f4e183aa731524bc946a34 SHA-1: 546491a835f6546f5a4826f31badd3000b468d64 SHA-256: 6991fcf002b4c91c2c621707b0b862bf154ec621aea4fb1da3851a633f38a584
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 high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other disposable hosting, suggesting it's used to distribute further malicious content or phish users. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://archism.ru/uplcv?utm_term=how+to+merge+two+pdf+docs PDF link annotation
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160746e078ceef---nazixudadufuzunezaleni.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/d59908c04e6190acc3878ad61dd98162/karumixubus.pdfIn PDF document text
    • http://granite1962.com/clients/869125/File/81101984813.pdfIn PDF document text
    • http://mdfgiare.com/upload/files/sufupixo.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c65c5109ab5---durojasarefigazafam.pdfIn PDF document text
    • http://piqiso.ru/userfiles/file/jamaxizixidub.pdfIn PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/1e22193ab6d5223efdf7793c6c3e13c2/15274238888.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/68b5370b0d5efb2e8bc5a6da68ec1a9c/68329333043.pdfIn PDF document text
    • https://annjulieskarpmo.com/userfiles/file/18867361461.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/53f88c4487f931402db729bfb7c651e2/67115905617.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ba9b1c44614---29850499403.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/e7bc65ec0eda7cc9ee0dd6309dacef09/tenoxawi.pdfIn PDF document text
    • https://valleyrestoration.net/home/apf/public_html/ckfinder/userfiles/files/12806363907.pdfIn PDF document text
    • https://shiphangnhanh.net/uploads/image/files/63029468958.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a19cb49cb43---rorevora.pdfIn PDF document text
    • http://hodinovysoused.cz/upload/file/dimasixipe.pdfIn PDF document text
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f014.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF014 16964 bytes
SHA-256: b55fb83f984bf2ec359777787c268905ff1a5f121e536d42165c4c340c4ae5a8
font_01_sfnt_off00011cb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CB2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000134c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134C9 10636 bytes
SHA-256: 6d145b2e9005c2017e6ff85ee7ff02882a76f46d38512741da832aa0aaeef89e