Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c20cf2349684c20…

MALICIOUS

PDF

84.3 KB Created: 2021-05-20 13:13:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-13
MD5: 031b97f6f5c2d2614cc2d9d92cef36e2 SHA-1: 89350d062ba5f6765901c92e2ab23b3b800e1bb5 SHA-256: 1c20cf2349684c2061ef26a772d976b1091ee8696de3ea492c896420088d2016
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of external links, many hosted on disposable domains or link farms, suggesting a tactic to distribute further malicious content or manipulate search engine results. The document body is heavily obfuscated and contains metadata indicating it was generated by wkhtmltopdf, a tool often used to create PDFs from web content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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.
  • 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://zuxadozi.weebly.com/uploads/1/3/4/6/134662888/8761527.pdf In PDF document text
    • https://cdn-cms.f-static.net/uploads/4383146/normal_6012d3d3c291e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420260/normal_5fe1d4dca0892.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481064/normal_605de0fbb4060.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423171/normal_602652b4e1abe.pdfIn PDF document text
    • https://rogetaguw.weebly.com/uploads/1/3/1/4/131407632/4158905.pdfIn PDF document text
    • https://basivuto.weebly.com/uploads/1/3/4/6/134646412/gugudixujifixewe.pdfIn PDF document text
    • https://bobifadilow.weebly.com/uploads/1/3/5/2/135295989/ninivuw.pdfIn PDF document text
    • https://natizupasa.weebly.com/uploads/1/3/1/4/131437725/mesepon_zitepo_sitikozamom.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381547/normal_6024297a0e427.pdfIn PDF document text
    • https://bixagitiwor.weebly.com/uploads/1/3/4/6/134618264/835a05da.pdfIn PDF document text
    • https://turonobofudub.weebly.com/uploads/1/3/4/4/134463989/nozavojezitoxep_vaxer.pdfIn PDF document text
    • https://gixeroparot.weebly.com/uploads/1/3/4/5/134586235/1168372.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478716/normal_600d553067414.pdfIn PDF document text
    • https://vanewuzopawibo.weebly.com/uploads/1/3/0/8/130814706/a2c0fd8.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/wb/ENAH/~3/bVCGPfG74RQ/wb?keyword=brandy%20norwood%20top%20songsPDF link annotation
    • https://s3.amazonaws.com/xeroguru/majobasazabijebedod.pdfIn PDF document text
    • https://s3.amazonaws.com/davawina/terijuzetawaxo.pdfIn PDF document text
    • https://s3.amazonaws.com/xalexojaxipud/vivov.pdfIn PDF document text
    • https://s3.amazonaws.com/lanaladu/tebiresizebe.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f6e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E6 5340 bytes
SHA-256: baaade1c0fe8330a7d8ff17d6e99795e75ca6ffd1e8338d96e44a1d10905d8f2
font_01_sfnt_off00010938.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10938 10948 bytes
SHA-256: 5ad35c80bb8af84b32cc25b65152729ab3e971a31dc08bea8745d5ca9d457c8f
font_02_sfnt_off00012ecf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ECF 16204 bytes
SHA-256: 6ff35bbcdef839a823e086214e5d609f702bf6b4484614f6c4b824d32b7fcc76