Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4b4ffa4190d0d7b…

MALICIOUS

PDF

49.1 KB Created: 2020-08-06 22:58:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 20323b8daf4f805f0781d090fe049cac SHA-1: 0a76d36228ca5727d5e3891ff509068748cc22ca SHA-256: f4b4ffa4190d0d7b91edb43d255b213dbb93630c6232e30650e5ac612484fef4
154 Risk Score

Malware Insights

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

The PDF was flagged as malicious by a critical heuristic due to its inclusion of a link to a known malicious redirector. It also contains a large number of external PDF links, characteristic of a link farm. The primary malicious IOC is the redirector URL, which likely leads to a phishing or malware delivery page. The document body itself is heavily obfuscated and contains embedded URLs.

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/pify?keyword=escala+apgar+recem+nascido+pdf
    • http://files.pioneerradio.org/uploads/1/3/0/7/130740112/modajebukuzozi.pdf
    • http://files.vizstationstl.com/uploads/1/3/0/7/130775859/tuzapuwub_xatadaxusa_jubujilod_jenobogevato.pdf
    • http://files.flipsidetoo.com/uploads/1/3/1/3/131383444/6c923a354c4d5d9.pdf
    • https://cdn.shopify.com/s/files/1/0429/6730/2295/files/97863757893.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/31906594002.pdf
    • https://cdn.shopify.com/s/files/1/0431/2514/5760/files/60217987041.pdf
    • https://cdn.shopify.com/s/files/1/0433/0379/6894/files/91854180031.pdf
    • https://cdn.shopify.com/s/files/1/0435/4536/2591/files/napuzibagejal.pdf
    • https://cdn.shopify.com/s/files/1/0447/2792/6937/files/couch_to_5k_reddit.pdf
    • https://cdn.shopify.com/s/files/1/0446/3240/8227/files/delete_heroku_app.pdf
    • https://cdn.shopify.com/s/files/1/0431/2173/7882/files/11720272108.pdf
    • https://cdn.shopify.com/s/files/1/0434/1468/3815/files/analogias_verbales_ejemplos.pdf
    • https://cdn.shopify.com/s/files/1/0434/1468/3815/files/38432308947.pdf
    • https://cdn.shopify.com/s/files/1/0431/3219/0876/files/bonopuwojosejiboresapel.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_off00007720.bin
bd5db2b5c6c86993bf3a0104acbc97d5af61254e0e630d1114cccf8d1d062476
pdf-font-stream PDF embedded font (sfnt) at offset 0x7720 5432 bytes
font_01_sfnt_off00008987.bin
5d84e01b8e27e44346c0c1fbb9916b2d25562de343de45709dd83dfed7579ae8
pdf-font-stream PDF embedded font (sfnt) at offset 0x8987 14912 bytes