Malicious PDF — malware analysis report

Static analysis result for SHA-256 5897a8e7e5022f98…

MALICIOUS

PDF

69.1 KB Created: 2021-04-02 10:26:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 0b361e043dfd32c023e6a9793c0a8b29 SHA-1: 23607370d2d8270d5bbad76c3386a63e890090b2 SHA-256: 5897a8e7e5022f9838034a1a5d10c8cc6794091678b5ca7ed152e0ffa2f8d829
244 Risk Score

Malware Insights

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

The sample is a PDF document that contains a large number of embedded links, many of which point to disposable hosting or redirector infrastructure. This suggests a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier also indicate maliciousness, likely related to phishing or trojan activity. No scripts were extracted, but the presence of numerous external links is the primary indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 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/strik?utm_term=how+many+calories+in+a+dunkin+donuts+large+caramel+macchiato In PDF document text
    • https://supavutoni.weebly.com/uploads/1/3/4/7/134713891/nabonazipedakegeluri.pdfIn PDF document text
    • https://cdn.sqhk.co/puvubuzu/tQwhhji/tilegakezaralesi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375356/normal_605a4a54792c2.pdfIn PDF document text
    • https://faxipanonuk.weebly.com/uploads/1/3/4/3/134352952/bediwamixi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487625/normal_606250943321b.pdfIn PDF document text
    • https://cdn.sqhk.co/kitujesijak/5iaDsgg/keto_chocolate_covered_strawberry_cheesecake.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388156/normal_6061b86d30dac.pdfIn PDF document text
    • https://cdn.sqhk.co/xukonobos/hhfoidd/zoguka.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451766/normal_6058c40dc3cf7.pdfIn PDF document text
    • https://cdn.sqhk.co/febapaji/NheticT/piano_chords_free.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413570/normal_600c72749ec9b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404124/normal_5fd15cbe6891f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477921/normal_60391a0e31442.pdfIn PDF document text
    • https://cdn.sqhk.co/lebudawojafi/hhfMgi6/mens_haircut_styles_2019_short.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/wonumafubij/how_much_do_machine_learning_engineers_make.pdfIn PDF document text
    • https://def26600-86c9-4442-a738-094ddf2992d1.filesusr.com/ugd/eb5a6a_42bbf040c6f94588bbe684c078738dca.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/natewared/ac_dc_anthology_guitar_tab_book.pdfIn PDF document text
    • https://66f9544f-8325-470d-a543-c07714603334.filesusr.com/ugd/4b2642_b995a549009b460681c5bc54a84d0bbc.pdf?index=trueIn PDF document text
    • https://0e733887-fd72-4d21-8b10-0a39cafbc931.filesusr.com/ugd/1e4d10_c91eb86f557746c598faad9fb854f2e9.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/pomaxa/bradford_white_water_heater_rg250t6n_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/dukexajuj/botebukevurenolaruva.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_off0000d10f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD10F 5572 bytes
SHA-256: 5624852de8e788d282d159f7a43856f622ba96202748e2ce04b465efcab804da
font_01_sfnt_off0000e3e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3E7 10132 bytes
SHA-256: 99aeaf8df27eccf898f94c21b0f5d547289d69db1653ebba2d7e3f95d7c20547