Malicious PDF — malware analysis report

Static analysis result for SHA-256 af184acb4c4ace91…

MALICIOUS

PDF

42.0 KB Created: 2020-07-14 11:23:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: a03308ae24edbbebea773b5aaaf656f7 SHA-1: 7dbc4b16560600d56420ed37f45aef3a018af494 SHA-256: af184acb4c4ace91ff61c5e58dd92fa3bd657ef81e902eb483f6119e042000b9
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to ttraff.ru. This indicates the document's primary purpose is to redirect users to malicious infrastructure. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create SEO-optimized content, which aligns with the PDF_SEO_LINK_FARM heuristic. The ML classifier also strongly flagged this PDF as malicious.

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=matokeo%20ya%20darasa%20la%20saba%20mwaka%202019%20pdf In PDF document text
    • http://files.higracecentral.org/uploads/1/3/1/4/131453984/525632.pdfIn PDF document text
    • http://files.rstne.com/uploads/1/3/1/4/131453531/somanulanako-juluk.pdfIn PDF document text
    • http://files.asiabizgroup.com/uploads/1/3/1/3/131398102/jeporafev_zunokut.pdfIn PDF document text
    • http://files.louisawarren.com/uploads/1/3/2/3/132303382/nokodaj.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/1/0428/0510/0707/files/4649921235.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/3699/0885/files/kirovul.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0427/7973/8278/files/50258343843.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/4093/9933/files/tobib.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/0844/2020/files/kaduripujimipuzaf.pdfIn PDF document text
    • https://kobukovojet.files.wordpress.com/2020/07/zavoxuvoxifa.pdfIn PDF document text
    • https://jevuboginov.files.wordpress.com/2020/07/2501624866.pdfIn PDF document text
    • https://gifamadez.files.wordpress.com/2020/06/nawexo.pdfIn PDF document text
    • https://razekusokil.files.wordpress.com/2020/06/bagad.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/9683/4212/files/48233281194.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/dusegu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/vuketunaxu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/bisadugizutojaririxenudep.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/3713/0914/files/11664504229.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/7783/6702/files/93392287080.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/pexivopagutufaxusezonav.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0133/9304/files/jisujadimarirapakizi.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/9164/8929/files/penemawozizej.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_off00006408.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6408 5708 bytes
SHA-256: c400e3cd7a682f0037f59b4245596a580e2b273cc716d82df36ab13b605813fb
font_01_sfnt_off0000779b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x779B 10124 bytes
SHA-256: ce78a850b4cb431452895935564e1cdd6a65fd9c42b62ac96abe4b2488e4c297