Malicious PDF — malware analysis report

Static analysis result for SHA-256 e0f4d528c071fb0d…

MALICIOUS

PDF

75.4 KB Created: 2021-07-12 20:26:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 1d71a4ac036f6cd950cdd13a6ac4396c SHA-1: 43c0d8eefecdeb418b2d96fa94a873d19cc01ddc SHA-256: e0f4d528c071fb0d5ae177eb290a228f6b4547e9b8a5678d16e0df92f42a9d10
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated maliciousness. A high-severity heuristic identified an image lure linking to an SEO redirector, specifically 'https://crewmak.ru/square?utm_term=cold+in+english', which is likely a phishing attempt for a free download. No scripts were extracted, but the PDF structure and URL suggest a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7703

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://crewmak.ru/square?utm_term=cold+in+english PDF link annotation
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60e82e6a4b964f05b84b6788/1625828970286/human_dna_sequence.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60ec7b170d838b6c850bf1bc/1626110743404/21994697023.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60e8a0620d7388251f4df45c/1625858146196/lean_in_synopsis.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://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_off0000c679.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC679 17508 bytes
SHA-256: 5e5bb8f440a0611b93667695e5af141937bf1aa563611f63aca062c816aec4bc
font_01_sfnt_off0000f3b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010bc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BC8 10200 bytes
SHA-256: 8228a50f8afe14a364ca07767ce3722ef8fd28a79a8da8fe7863f9a9130c516b