Malicious PDF — malware analysis report

Static analysis result for SHA-256 d21be4a736c76a88…

MALICIOUS

PDF

42.9 KB Created: 2020-08-15 13:16:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 07b8055a61b5a274263b1229a2d5bcad SHA-1: 29b0e4eeb2a1bcb896f0ea5e2770eac19e4a1066 SHA-256: d21be4a736c76a88e15d40c76b86746cfb4b66acdb4ea84bba15c6fede843707
152 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 'https://ttraff.com/wb?keyword=percentage%20questions%20for%20bank%20po%20pdf%20download'. This URL is likely part of a phishing or scam campaign, attempting to trick users into downloading malicious content or visiting further compromised sites. The document body also contains this URL and numerous other links to PDF files, many hosted on Shopify, suggesting a link farm or SEO poisoning tactic to increase visibility. The ML classifier also strongly flagged this PDF as malicious.

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.com/wb?keyword=percentage%20questions%20for%20bank%20po%20pdf%20download
    • http://kakisosa.schoolofswedishfish.com/uploads/1/3/0/7/130739274/4232660.pdf
    • https://cdn.shopify.com/s/files/1/0431/3271/5163/files/subject_verb_agreement_inverted_sentences_worksheets.pdf
    • https://cdn.shopify.com/s/files/1/0437/4223/2725/files/85094113296.pdf
    • https://cdn.shopify.com/s/files/1/0433/3902/2485/files/52798798653.pdf
    • https://cdn.shopify.com/s/files/1/0437/2840/4632/files/25991461371.pdf
    • https://cdn.shopify.com/s/files/1/0433/4498/6280/files/91272946593.pdf
    • https://cdn.shopify.com/s/files/1/0430/0849/1673/files/nuponiw.pdf
    • https://cdn.shopify.com/s/files/1/0432/2174/5823/files/supibokibidusef.pdf
    • https://cdn.shopify.com/s/files/1/0437/2588/1498/files/fundamentals_of_electrical_engineering_mcqs.pdf
    • https://cdn.shopify.com/s/files/1/0434/1540/4711/files/kilivivoketovovawexiwexup.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000058f6.bin
6c3b8cebead576636ae51e87cfad12cf91af7812c3935de10407254c17bfe3b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x58F6 5628 bytes
font_01_sfnt_off00006c28.bin
2b9ab276fa057114946d8af17a0d074011cb1865ca6d7c7c560533a68cf78a2e
pdf-font-stream PDF embedded font (sfnt) at offset 0x6C28 10764 bytes
font_02_sfnt_off00009090.bin
cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34
pdf-font-stream PDF embedded font (sfnt) at offset 0x9090 4324 bytes