Malicious PDF — malware analysis report

Static analysis result for SHA-256 16f2ead6757ce398…

MALICIOUS

PDF

44.8 KB Created: 2020-07-31 11:39:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: bec4099fa2bba83f2a2ae74dba72ace3 SHA-1: 4abfb1a38212aece297ac654c11a88291d7021be SHA-256: 16f2ead6757ce398cf52327eaf0a3214dfaee18bb7887b0c13896d5c6ff249fb
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a heuristic firing for PDF_MALICIOUS_REDIRECTOR_LINK, indicating it directs users to malicious infrastructure. Additionally, PDF_SEO_LINK_FARM suggests a large number of external links, many of which are likely malicious or part of a link farm. The ML classifier also strongly flagged this PDF as malicious. The embedded URLs and the document body, which appears to be obfuscated text related to academic PDFs, support the conclusion that this document is designed to redirect users to malicious sites.

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=differential+calculus+by+gorakh+prasad+free+download+pdf
    • http://files.rhearuben.com/uploads/1/3/1/0/131070166/3771581.pdf
    • http://files.partnersinhopeusa.org/uploads/1/3/0/7/130739234/gilaberix.pdf
    • http://files.annalisereinhardtphoto.com/uploads/1/3/0/8/130874431/620f78c6de76b9.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0434/8638/0189/files/kabedizovubife.pdf
    • https://cdn.shopify.com/s/files/1/0433/4836/1375/files/mesanusatu.pdf
    • https://cdn.shopify.com/s/files/1/0435/8642/0893/files/bazegojig.pdf
    • https://cdn.shopify.com/s/files/1/0432/3000/3358/files/6009591790.pdf
    • https://cdn.shopify.com/s/files/1/0433/9426/9333/files/86580854491.pdf
    • https://cdn.shopify.com/s/files/1/0431/5496/4637/files/kasesikadajefasa.pdf
    • https://cdn.shopify.com/s/files/1/0430/8277/6725/files/13260044066.pdf
    • https://cdn.shopify.com/s/files/1/0433/7703/3372/files/94716720738.pdf
    • https://cdn.shopify.com/s/files/1/0433/1926/3397/files/visimuguze.pdf
    • https://cdn.shopify.com/s/files/1/0428/5949/5590/files/xipawebogorava.pdf
    • https://cdn.shopify.com/s/files/1/0432/9966/8121/files/40772252487.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006f99.bin
96d33484a0852e905ec2247ac0d9d8f32762be083da11005293056e0f2ee191c
pdf-font-stream PDF embedded font (sfnt) at offset 0x6F99 5696 bytes
font_01_sfnt_off0000830d.bin
48c7c9d8c47a78229bf5a9b5f41dc61043306f761f687c78289bccff42a444b3
pdf-font-stream PDF embedded font (sfnt) at offset 0x830D 10208 bytes