Malicious PDF — malware analysis report

Static analysis result for SHA-256 b61c60b9a21716b4…

MALICIOUS

PDF

75.7 KB Created: 2021-07-12 23:23:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: d4eeb953ef263a93303d5f63ddc1ddbb SHA-1: 0950370d04b3d10ce9505eb392b3765bf6dc4488 SHA-256: b61c60b9a21716b40ecd262533791d7a331a05afbafd3d58630df22178eacc87
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a high-severity heuristic indicating it's a phishing lure that redirects to an external URL. The ML classifier and ClamAV also flagged this file as malicious. The embedded URL, https://synerhu.ru/square?utm_term=how+many+cups+of+flour+in+a+quart, is the primary indicator of compromise, likely leading to a phishing page or malware download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7483

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://synerhu.ru/square?utm_term=how+many+cups+of+flour+in+a+quart PDF link annotation
    • https://static1.squarespace.com/static/60aac4dd19f082755c4e5c69/t/60e76d17b96d4839c800e450/1625779479403/mexuguzejiwajoxa.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60e8154ca3609a707bae73ac/1625822540404/54390118648.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac52a97a1d73ddacfe14c/t/60ec90aac32416487af0861d/1626116266797/karma_thoughts_in_english.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4dd19f082755c4e5c69/t/60ec9b4e51a87c5d75ae18b5/1626118990479/confirmation_of_contract.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_off0000c6a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6A3 16436 bytes
SHA-256: 5acccc56fb3b0e096beeeaa6c6efabc437a0c35a91b765ed3cbbce0880706c78
font_01_sfnt_off0000f167.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF167 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001097e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1097E 10944 bytes
SHA-256: 58affc479bdb871e5228484bf372beceaba45753a5f5f998b33a93ff577d0c51