Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a4b23e19e5b928d…

MALICIOUS

PDF

58.1 KB Created: 2020-07-24 01:11:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: 1d57bad4395aa96cc6f41e7733cfccb0 SHA-1: ca1728413619cf62b5aeaeb2deadb496c0b1366b SHA-256: 1a4b23e19e5b928d13a313970e38e574e0415db5c4f3f5790ded6a8ff387fe5e
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a critical heuristic firing for a malicious redirector link pointing to 'ttraff.ru', which is part of a link farm designed to manipulate search engine results. The document body, though heavily obfuscated, contains references to 'Elsevier vaccine immunology pdf' and 'wkhtmltopdf', suggesting a lure to entice users to click the malicious link. The presence of numerous external PDF links, many hosted on Shopify, further supports the link farm tactic.

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://ttraff.ru/wb?keyword=elsevier%20vaccine%20immunology%20pdf In PDF document text
    • http://files.christinebrumbaughdesign.com/uploads/1/3/0/7/130739376/2056645.pdfIn PDF document text
    • http://files.bomberheights.org/uploads/1/3/1/8/131856034/setovafores_warija_derejezulopu.pdfIn PDF document text
    • http://files.steelrhythm.com/uploads/1/3/1/3/131380875/65bc2f6dd3e2.pdfIn PDF document text
    • http://files.catholiclaity.us/uploads/1/3/2/8/132814342/tolun-pijogowi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/2324/5216/files/dulatefasaronojekamov.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0107/7142/files/najokugatunira.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/1970/6269/files/84078228333.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/9019/8180/files/80605505049.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/9064/8996/files/zupasadixidumuwojid.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/5104/9370/files/kevol.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/0668/1497/files/48837771822.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/7272/4892/files/woponekozoxituwi.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/9087/0423/files/91121571242.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/7940/1632/files/mujokakedepo.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/0029/8648/files/45768200824.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/4402/8068/files/vezaderedameje.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/7526/3909/files/pevigelaru.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 PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000a4c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xA4C1 5396 bytes
SHA-256: fae8017df8ffcd336d007549545d021f65d48b5471eadb55d95fbf5d696ea264
font_01_sfnt_off0000b704.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB704 10768 bytes
SHA-256: 3ea4c78605ad04a21eebda96c0f37ded9d44982cc3aafd4eb6df4d87c00bbddb