Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b77ef90b59f14d…

MALICIOUS

PDF

64.7 KB Created: 2020-11-18 12:28:37 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fd00d3af573e67919eee962eabbdc969 SHA-1: 5a46e77a5b579d808e8a647695bc26c89b49b6dd SHA-256: 21b77ef90b59f14d3d703e7621f33374b7251010cd1945ba3ed276a9038df556
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links, many of which point to potentially malicious domains, as indicated by the PDF_SEO_LINK_FARM heuristic. One prominent URL, 'https://trafffe.ru/strik?utm_term=introduction+to+animal+science+5th+edition+pdf', is presented as a search result, suggesting a lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://trafffe.ru/strik?utm_term=introduction+to+animal+science+5th+edition+pdf
    • https://cdn-cms.f-static.net/uploads/4489599/normal_5fadae1537a25.pdf
    • https://moxoviwepikiwu.weebly.com/uploads/1/3/2/8/132814726/nilomaridemak.pdf
    • https://vebifejelib.weebly.com/uploads/1/3/0/7/130775119/vemek.pdf
    • https://xukaxikerebata.weebly.com/uploads/1/3/4/0/134042698/vofazemosorarad_zekamuwunibes.pdf
    • https://cdn-cms.f-static.net/uploads/4390095/normal_5f8df7a367324.pdf
    • https://cdn-cms.f-static.net/uploads/4383128/normal_5f9308997bcac.pdf
    • https://cdn-cms.f-static.net/uploads/4366055/normal_5f972d59b4fee.pdf
    • https://cdn-cms.f-static.net/uploads/4413368/normal_5fb32d7637159.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/tarajix/tafebububexerokilafetotu.pdf
    • https://uploads.strikinglycdn.com/files/f368ba4d-b2da-401e-90f7-93a548df8ce9/family_tree_maker_companion_guide_2017.pdf
    • https://s3.amazonaws.com/ganubifirigevi/28756232205.pdf
    • https://s3.amazonaws.com/jixerubowi/12458414016.pdf
    • https://s3.amazonaws.com/gurowozenupifi/short_brown_wig_with_fringe.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_off0000bd8e.bin
96c966d3c9bcf4367ea82eff7df5668e4deb7c2c6470b59e3adb72625d08c8ac
pdf-font-stream PDF embedded font (sfnt) at offset 0xBD8E 5456 bytes
font_01_sfnt_off0000cff4.bin
748f2bc5440fcfd8b5917587e4bd0f10299ff298267c5ee57e69d48854c3ecf0
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFF4 10588 bytes