Malicious PDF — malware analysis report

Static analysis result for SHA-256 51c5a7852842fea8…

MALICIOUS

PDF

71.5 KB Created: 2020-11-13 12:39:22 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c804187a943f2c7d72a21b41df76bd20 SHA-1: 5e189eac82db1d56668a3281c95faf8f77ed3c18 SHA-256: 51c5a7852842fea8bd7cb7303613e6dba06114854d6103123fed504e4e052c99
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicate a high probability of maliciousness. The heuristic PDF_SEO_LINK_FARM indicates the document contains a large number of external links, likely for SEO manipulation or to redirect users to malicious sites. One of the embedded URLs, https://trafffi.ru/123?utm_term=monterey+high+school+tn+phone+number, suggests a phishing or scam attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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
  • 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://trafffi.ru/123?utm_term=monterey+high+school+tn+phone+number
    • https://cdn-cms.f-static.net/uploads/4381289/normal_5fadd11403059.pdf
    • https://cdn-cms.f-static.net/uploads/4405179/normal_5f9a566339425.pdf
    • https://cdn-cms.f-static.net/uploads/4365628/normal_5fada01dcb9fb.pdf
    • https://vezupololepabuk.weebly.com/uploads/1/3/4/6/134600483/pevenagunol_kapobuki_jezadenepof_vapenesurumil.pdf
    • https://cdn-cms.f-static.net/uploads/4368982/normal_5f9b5f71eed06.pdf
    • https://waxatuvew.weebly.com/uploads/1/3/4/3/134371429/3082196.pdf
    • https://cdn-cms.f-static.net/uploads/4371505/normal_5f8968aecc0ff.pdf
    • https://cdn-cms.f-static.net/uploads/4380705/normal_5fa1a4b88e126.pdf
    • https://cdn-cms.f-static.net/uploads/4366622/normal_5f8ab9c7bac45.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/gumegulaxi/18899687350.pdf
    • https://uploads.strikinglycdn.com/files/5d0c303e-b4f2-4b5a-87fc-38d56872f25c/eres_mia_y_solo_mia_translation_english.pdf
    • https://uploads.strikinglycdn.com/files/cbc8e390-4e96-4fa4-aaae-d09f87e24630/warapisogizuraxikakot.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_off0000d9c0.bin
008ead9501739f87c4d6823c8c5624f6c9366dc023a40dc81d1856deb4f0126f
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9C0 5384 bytes
font_01_sfnt_off0000ec03.bin
0442008f38643758277c02a17016c7b7316d5c4bf65c1442ec093ac8bec7b1ca
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC03 11184 bytes