Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c81f70479e31a7e…

MALICIOUS

PDF

72.7 KB Created: 2021-02-27 14:12:02 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: fc30e941868039ea5f6b7b18d616bf0a SHA-1: 5f36d1a2899865637b1f73093ef99713faf3de6c SHA-256: 3c81f70479e31a7e12ca26e79d83dee509821b84efc55b86eee4fac64359c320
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was identified as malicious by multiple heuristics and a machine learning classifier. It contains a large number of embedded links, many pointing to disposable domains and redirector infrastructure, suggesting a link farm or phishing campaign. The presence of a link to a known malicious redirector further supports this. No scripts were extracted, but the PDF structure itself facilitates the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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.
  • 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://crophysi.ru/wb?keyword=frank%20netter%20anatomy%20coloring%20book In PDF document text
    • http://vash-komfort5.ru/ielts_essential_guide_speaking_test_1zx2dz.pdfIn PDF document text
    • https://cdn.sqhk.co/zubixola/igghbie/mansions_of_madness_2nd_edition_expansion_order.pdfIn PDF document text
    • https://vebavorosufate.weebly.com/uploads/1/3/4/7/134742301/fokanoru_kilakozusoduf.pdfIn PDF document text
    • http://rentline.pro/matinalinephz1s9.pdfIn PDF document text
    • http://triple-doska4.club/vagodurojekeva10mlm.pdfIn PDF document text
    • http://thelandofbadideas.com/dujafuzurovavalunutuesmm.pdfIn PDF document text
    • http://burrrhey.tech/zevexutev23rlx.pdfIn PDF document text
    • https://remejatezikame.weebly.com/uploads/1/3/1/0/131070309/xigoxumav-tabovezediki-pelujuz-lezoneke.pdfIn PDF document text
    • https://ripaduwik.weebly.com/uploads/1/3/5/3/135311581/304b345.pdfIn PDF document text
    • http://hr-insider.com/ripaji6z696.pdfIn PDF document text
    • https://tuzunogosur.weebly.com/uploads/1/3/0/8/130815213/10425d4163c77.pdfIn PDF document text
    • http://muldwych.com/21473396281y9cr2.pdfIn PDF document text
    • https://tugadebijo.weebly.com/uploads/1/3/4/0/134042488/ac27973.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/badodemebo/ee_voicemail_settings_android.pdfIn PDF document text
    • https://s3.amazonaws.com/rijaliwiguvex/59456235787.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF1A 5200 bytes
SHA-256: 3d96a948aa3ca06eefe9b598bd37a0612ade5eaab18cbe72bce8af444438282d
font_01_sfnt_off0000f0cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0CC 10964 bytes
SHA-256: abf9b9dd1d9061668d049539d68f63a3c5e89d539a7c2975de5cedc019ebb2d6

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