Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2b623ec623bc938…

MALICIOUS

PDF

39.2 KB Created: 2020-08-12 03:18:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: eae8fd8596ea64a3755e2284e52d47f2 SHA-1: 1ee96016b7f3fa89722249d486b9a986c9290758 SHA-256: b2b623ec623bc938a7d1d356c186b609f82433722743aae5f6757517a312e6c7
154 Risk Score

Malware Insights

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

The PDF contains a link farm designed to SEO-abuse, directing users to a malicious redirector at 'https://ttraff.cc/pify?keyword=ca+cpt+accounting+book+pdf'. The document body, though heavily obfuscated, contains references to accounting books and the malicious URL, suggesting a lure to trick users into clicking the link. The ML classifier strongly flagged this PDF as malicious, supporting the observed redirector link.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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.cc/pify?keyword=ca+cpt+accounting+book+pdf
    • http://luxivil.carpetcleanoahu.com/uploads/1/3/1/3/131383791/258f7378db3474.pdf
    • http://files.yeeg.co.uk/uploads/1/3/1/4/131408170/4274033.pdf
    • http://files.geras.sk/uploads/1/3/1/3/131398224/kimal_folukisi_bubepiwil.pdf
    • http://files.riskescience.com/uploads/1/3/0/7/130776644/395ba5.pdf
    • https://cdn.shopify.com/s/files/1/0430/8815/0690/files/gibapedodunuk.pdf
    • https://cdn.shopify.com/s/files/1/0431/0600/9255/files/nituwotonekapileg.pdf
    • https://cdn.shopify.com/s/files/1/0438/4695/9261/files/que_es_psicologia_comunitaria.pdf
    • https://cdn.shopify.com/s/files/1/0440/8947/5237/files/38015416.pdf
    • https://cdn.shopify.com/s/files/1/0438/9352/2587/files/mevalakiborozezex.pdf
    • https://cdn.shopify.com/s/files/1/0434/0400/1443/files/retencion_placentaria_en_equinos.pdf
    • https://cdn.shopify.com/s/files/1/0431/9241/8468/files/befevozamumiwitusesavim.pdf
    • https://cdn.shopify.com/s/files/1/0431/9969/2958/files/paludeximegelule.pdf
    • https://cdn.shopify.com/s/files/1/0441/0304/1176/files/rabbit_farming_business_plan_south_africa.pdf
    • https://cdn.shopify.com/s/files/1/0433/6192/7318/files/80706354493.pdf
    • https://cdn.shopify.com/s/files/1/0432/9147/6133/files/80321062590.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/kufotiniponekurek.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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005c10.bin
dc572262145ab4cd94d94cfb9d49bb2f122a58fc02e67054b4611590cb75042e
pdf-font-stream PDF embedded font (sfnt) at offset 0x5C10 5124 bytes
font_01_sfnt_off00006d8d.bin
ab7fcaac32eef2657b6bc158c7fa1e2448fe1997464a82fa5f912d929af3f7cb
pdf-font-stream PDF embedded font (sfnt) at offset 0x6D8D 10016 bytes