Malicious PDF — malware analysis report

Static analysis result for SHA-256 451d5169f8c1e6b7…

MALICIOUS

PDF

45.6 KB Created: 2020-10-05 10:40:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 400e31199886e74684ef78e30e7cdcd4 SHA-1: 5bb2cb3832d07dc206b79ce26a437f7f36801c74 SHA-256: 451d5169f8c1e6b7db316a59691491ec32bc25e040caf25c68facdf6699cf2e4
194 Risk Score

Malware Insights

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

This PDF document contains a large number of embedded URLs, many of which point to a redirector service. The document body text, while appearing to discuss book templates, is likely a lure to encourage users to click the malicious link. The primary malicious URL identified is https://cctraff.ru/strik?keyword=book+foreword+template, which is flagged as a known malicious redirector. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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.
  • 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://cctraff.ru/strik?keyword=book+foreword+template In PDF document text
    • http://pofepawim.robertlloydartny.com/uploads/1/3/2/3/132303374/ropoxerixuviri.pdfIn PDF document text
    • http://files.jslegalservices.com/uploads/1/3/1/3/131380618/nepinanutoveso-zoxilolugim.pdfIn PDF document text
    • http://files.blackhillsbalinese.com/uploads/1/3/1/1/131164520/tepigagowuwu.pdfIn PDF document text
    • http://japixowap.johnurquharticles.com/uploads/1/3/1/4/131437299/822423.pdfIn PDF document text
    • http://files.valhallamassagetherapy.com/uploads/1/3/1/4/131437657/3bd42f8e5c0d8bd.pdfIn PDF document text
    • http://www.ascendercorp.com/In extracted file (font_00_sfnt_off00006de8.bin)
    • http://www.ascendercorp.com/typedesigners.htmlIn extracted file (font_00_sfnt_off00006de8.bin)
    • https://cdn.shopify.com/s/files/1/0437/7536/1185/files/40479455231.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0437/2883/0632/files/spanish_indefinite_articles.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0484/8766/1730/files/koxapari.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0459/8824/9757/files/allstar_garage_door_opener_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/708a893c-a24d-48ab-86b3-4f1a65aa9778/69725260383.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bb0fffd2-d199-4dfa-8808-fb1c2e06e5d5/25082958634.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0480/6308/6756/files/download_assassins_creed_identity_apk_revdl.com.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/2518/7491/files/black_friday_electric_scooter_sale.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/8865/0135/files/the_maze_runner_cast.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0437/1188/9573/files/form_function_content_context.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 extracted file (font_00_sfnt_off00006de8.bin)

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006de8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6DE8 5212 bytes
SHA-256: e3d427147b62a79928134674bdef3c27b624d7befd7591331c14bf3f4efe8623
font_01_sfnt_off00007f9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7F9E 1800 bytes
SHA-256: a36eee06fef6ce219692c4ec918276ac99413e4fd1e3666e4031624f9289d620
font_02_sfnt_off0000882a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x882A 9772 bytes
SHA-256: e1ef3a34735d64e4bc2acd8e851378704fa52ab5c75b15a7dedc04cb4813b8f0