Malicious PDF — malware analysis report

Static analysis result for SHA-256 a41a40fed9617045…

MALICIOUS

PDF

39.4 KB Created: 2020-07-20 23:30:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: da7e7a80c89ce9db13cbef070d2a54fe SHA-1: 283067f8aef7c5acd22ce369ce87bd4523849819 SHA-256: a41a40fed96170454da2dab09b799ee2ddbc34985d23c44f4df0513da3c1541e
194 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains text related to 'continuity of care', likely a lure. The ML classifier strongly indicates maliciousness, and the presence of a link farm suggests an attempt to game search engines or distribute malicious content.

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=continuity%20of%20care%20the%20transitional%20care%20model%20pdf In PDF document text
    • http://files.mrscooksbayhighscienceclass.com/uploads/1/3/1/6/131637306/9322073.pdfIn PDF document text
    • http://files.jagodadobecka.com/uploads/1/3/0/7/130776408/5744682.pdfIn PDF document text
    • http://files.deeperhealing.net/uploads/1/3/2/6/132695467/9e8c30aba0c2b1.pdfIn PDF document text
    • http://files.cbdstoremi.com/uploads/1/3/1/3/131379049/vubegiju.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/1/0428/7276/6631/files/30975254416.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9599/9129/files/subefumudijasakamulofom.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/21154843933.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/3258/4098/files/75854131160.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0427/7341/4055/files/16763642728.pdfIn PDF document text
    • https://senodakezol.files.wordpress.com/2020/06/lemeparoje.pdfIn PDF document text
    • https://mulosegavo.files.wordpress.com/2020/06/92053149863.pdfIn PDF document text
    • https://narebifene.files.wordpress.com/2020/07/kuboziloto.pdfIn PDF document text
    • https://luxuvolug.files.wordpress.com/2020/07/kinew.pdfIn PDF document text
    • https://kuvizelabu.files.wordpress.com/2020/07/mijuxa.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/4848/5535/files/48973072922.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/kikurum.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/6888/3106/files/tadevosenozem.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/lozafawofife.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/6104/3605/files/xujaba.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/3428/0087/files/kilodiwokinuxenaput.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/nazowexoratusitufunu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/5346/6271/files/44789508313.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_off00005d35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5D35 5404 bytes
SHA-256: 74e0184b9fb263dbc77f2f3372244a282c6be31f0c5bfa7cb52e56878c380377
font_01_sfnt_off00006f73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6F73 9404 bytes
SHA-256: 963ca7e36b5f4906c5b2751de132c9c2b5a438dd396d8ad18db78ed501897a94