Malicious PDF — malware analysis report

Static analysis result for SHA-256 13a3567f0fb2a8a0…

MALICIOUS

PDF

61.5 KB Created: 2020-11-22 08:42:00 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: b4ef736c7afa571923a7b81269b8553c SHA-1: 10c917883768d12e140b6ec71fc06207bc4751d1 SHA-256: 13a3567f0fb2a8a0187b6f463db02543fcd8a5f72adaa2e587dca5cdaba17dff
214 Risk Score

Malware Insights

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

The PDF contains multiple embedded links, with one specifically pointing to a known malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of numerous external PDF links suggests a link farm or SEO poisoning attempt to obscure the malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://cctraff.ru/123?utm_term=the+reproductive+system+worksheet+answers
    • https://cdn-cms.f-static.net/uploads/4383295/normal_5fa9a1f7b5d7e.pdf
    • https://sofabavoxikavup.weebly.com/uploads/1/3/4/6/134636307/14b1a692bfc.pdf
    • https://cdn-cms.f-static.net/uploads/4365612/normal_5f8730fb1f588.pdf
    • https://cdn-cms.f-static.net/uploads/4409610/normal_5fb47008bd4d4.pdf
    • https://cdn-cms.f-static.net/uploads/4427498/normal_5f99c994d7b30.pdf
    • https://cdn-cms.f-static.net/uploads/4365582/normal_5f86fcdb5387c.pdf
    • https://cdn-cms.f-static.net/uploads/4493891/normal_5fb37cb8cb8eb.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/a16107fc-700b-4506-bfa2-e762b46319b3/ipad_mini_model_md531ll_a_generation.pdf
    • https://s3.amazonaws.com/tuzamada/free_download_surat_yasin_dan_tahlil.pdf
    • https://s3.amazonaws.com/suximawo/map_of_etna_maine.pdf
    • https://uploads.strikinglycdn.com/files/917af1b8-faa4-4373-895f-650f09df68a1/austin_isd_blend_login.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b3a1.bin
d132a16fcc5b9bf07e3e4e4771a0dee9a19dc716c8813be6dfe24a34902b63f4
pdf-font-stream PDF embedded font (sfnt) at offset 0xB3A1 5548 bytes
font_01_sfnt_off0000c670.bin
2aad02a03f2b986709e4622649b7a10c2c7a1f795a6a9a852440dc3b57d7f8e2
pdf-font-stream PDF embedded font (sfnt) at offset 0xC670 10212 bytes