Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd86c4ccd21dcbe1…

MALICIOUS

PDF

37.4 KB Created: 2020-08-16 14:43:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: caa05cd30efc75c646c06eb1887dc424 SHA-1: 58bc8c86f73d161eda31b4a1e350ae9566b59254 SHA-256: bd86c4ccd21dcbe1425425fb7951d7ae55a1448aeda73c1c1acde2c193c49514
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many pointing to Shopify domains, but one critical link directs to a known malicious redirector. The document body, though heavily obfuscated, contains the text 'Food vocabulary in spanish worksheets' and the malicious URL, suggesting a lure to a phishing or malware distribution site. The ML classifier strongly supports the malicious verdict.

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=food+vocabulary+in+spanish+worksheets
    • http://files.alchemyguitarwerks.com/uploads/1/3/1/8/131858592/205762.pdf
    • http://kunajo.thecuriouskind.org/uploads/1/3/0/9/130969352/padapekusawexet.pdf
    • http://besudu.bestcheaptrips.net/uploads/1/3/1/3/131381720/1a670a9193.pdf
    • https://cdn.shopify.com/s/files/1/0432/1801/0274/files/farmville_2_country_escape_cheats.pdf
    • https://cdn.shopify.com/s/files/1/0436/8711/6965/files/grant_cardone_closes.pdf
    • https://cdn.shopify.com/s/files/1/0432/6742/4416/files/85335380904.pdf
    • https://cdn.shopify.com/s/files/1/0430/6986/6133/files/95849742042.pdf
    • https://cdn.shopify.com/s/files/1/0436/3704/7449/files/effects_of_globalization_on_environment.pdf
    • https://cdn.shopify.com/s/files/1/0428/1358/7622/files/evangelios_apocrifos_del_nuevo_testamento.pdf
    • https://cdn.shopify.com/s/files/1/0431/4087/4408/files/16642402308.pdf
    • https://cdn.shopify.com/s/files/1/0437/8905/8206/files/gasemuwuxixufod.pdf
    • https://cdn.shopify.com/s/files/1/0437/3122/2682/files/mulokulapub.pdf
    • https://cdn.shopify.com/s/files/1/0430/0403/5221/files/46101047761.pdf
    • https://cdn.shopify.com/s/files/1/0430/0659/1127/files/besejagakibizurato.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_off000053e5.bin
34a40494d46b5022042c7adf2fca67c7536cbf2dedd7051afef064d10974ce16
pdf-font-stream PDF embedded font (sfnt) at offset 0x53E5 5572 bytes
font_01_sfnt_off000066e6.bin
70d702ab665adb69d1705b5cbb54edddd60726c0c30c2fc5eccd0d7b75b5069d
pdf-font-stream PDF embedded font (sfnt) at offset 0x66E6 9832 bytes