Malicious PDF — malware analysis report

Static analysis result for SHA-256 19dfacc87bda2f62…

MALICIOUS

PDF

68.4 KB Created: 2020-12-18 01:48:37 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: a93e361f53c7b8a296d89970dc28c8b7 SHA-1: 58ba4901f8d4df7c2362d2cb422cf2fddf0d25b9 SHA-256: 19dfacc87bda2f62979bc469cb144ea4ba3ac1c7be0b0fce434d2778d6831fe8
214 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan and exhibits critical heuristic firings for malicious redirector links and a link farm. The embedded URL points to a known malicious redirector, indicating an attempt to lead the user to a harmful site. The presence of numerous external links, including one to a PDF on AWS S3, suggests a tactic to obscure the malicious destination or to distribute further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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/strik?utm_term=lucky+star+television+show+characters
    • https://konevumi.weebly.com/uploads/1/3/4/3/134399330/6261711.pdf
    • https://cdn-cms.f-static.net/uploads/4377403/normal_5f963c717b680.pdf
    • https://cdn-cms.f-static.net/uploads/4446774/normal_5fbbe1b76e563.pdf
    • https://gavabedaxi.weebly.com/uploads/1/3/4/9/134902957/ab03ea1c.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/dorulusof/10612221406.pdf
    • https://s3.amazonaws.com/salosibejodod/convert_html_to_nodejs.pdf
    • https://uploads.strikinglycdn.com/files/3b28e2cf-8273-4019-9b63-a463530d7cf8/90274717103.pdf
    • https://uploads.strikinglycdn.com/files/7199208b-a21d-45d8-8055-ddcb41832813/59453622742.pdf
    • https://uploads.strikinglycdn.com/files/b60ff320-19fb-46df-8244-2b91dd80e69e/fasepumosutitenuxutumetuv.pdf
    • https://uploads.strikinglycdn.com/files/33edfaa2-f85e-4837-a4f1-2e5d7ddd5a0c/wokosasewidoxelesotevu.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_off0000cf4e.bin
da166616568de01f337aa79e7cd3d429935e3d6bc02f843526a53b3781a1d468
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF4E 5148 bytes
font_01_sfnt_off0000e0f0.bin
b0cabd000508bd5e3470fc76154d1b809fcd61bf9c0b9bd02b21e25c70e956a5
pdf-font-stream PDF embedded font (sfnt) at offset 0xE0F0 10640 bytes