Malicious PDF — malware analysis report

Static analysis result for SHA-256 f21dcd29a6b272fe…

MALICIOUS

PDF

77.2 KB Created: 2021-07-14 05:36:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: c37bb8e207c4251e768a26229fe2d1d6 SHA-1: cbb90b3639f0ca5dd3f909b66f3cdb29c3346c06 SHA-256: f21dcd29a6b272fe42393ca05c543b9b6b8bfc395b7c97efbe347405d2c2ae54
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, with high-severity heuristics indicating it contains a redirector link. The embedded URL `https://laborke.ru/square?utm_term=lime+jello+with+cream+cheese` is flagged as a potential phishing lure. No scripts were extracted, but the overall structure and heuristics point to a phishing attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7691

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://laborke.ru/square?utm_term=lime+jello+with+cream+cheese PDF link annotation
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60edb35a1a2ce466740e1131/1626190682314/tudikeroromijupigurukeki.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60ee4215462f394a1e429dd8/1626227221382/how_to_unlock_a_windows_10_laptop_without_password.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60e94f242dabf2723555ca68/1625902884988/jumomafubi.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_off0000cc81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC81 10564 bytes
SHA-256: b561a0ed4a74c2c464dfea069a366ea44357b7407f581d0677a96624fb77ab28
font_01_sfnt_off0000e49b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE49B 16420 bytes
SHA-256: 2a734b5110c173b522b1f147ae990db76a3ec221821f8f09f1f7681f6e28515e
font_02_sfnt_off00010f6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F6A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1