Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c988d32e0fd1317…

MALICIOUS

PDF

41.7 KB Created: 2020-08-04 06:03:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f0b5445bfd68464d6de42c5f8af291d7 SHA-1: 0f74e2730b1737d652e44475fca7478d6f5bbf1e SHA-256: 1c988d32e0fd13171f39d0c55459801c301b7b104e806f86cb14363c7d77e2bd
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 of which point to a link farm hosted on cdn.shopify.com and redirect through ttraff.ru. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK confirms that ttraff.ru is known malicious infrastructure. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains the URL https://ttraff.ru/pify?keyword=grade+1+math+worksheets+pdf+free, suggesting a lure to entice users to click on malicious links.

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.ru/pify?keyword=grade+1+math+worksheets+pdf+free
    • http://pogabep.17southband.com/uploads/1/3/1/4/131437423/ca0757ce06.pdf
    • http://files.soireeseventsrentals.com/uploads/1/3/2/6/132681880/bizebubud.pdf
    • http://files.extrordinarycounseling.com/uploads/1/3/1/3/131379948/09a2b9e.pdf
    • https://cdn.shopify.com/s/files/1/0431/8245/7000/files/mizijuritopel.pdf
    • https://cdn.shopify.com/s/files/1/0428/8577/5519/files/ligikutubutijes.pdf
    • https://cdn.shopify.com/s/files/1/0431/9261/5073/files/58800755156.pdf
    • https://cdn.shopify.com/s/files/1/0435/5011/3943/files/centripetal_force_lab.pdf
    • https://cdn.shopify.com/s/files/1/0429/7441/2949/files/dowobezipudekawajesiwosi.pdf
    • https://cdn.shopify.com/s/files/1/0431/0623/8613/files/57710794428.pdf
    • https://cdn.shopify.com/s/files/1/0428/9812/9062/files/wuzoxeralu.pdf
    • https://cdn.shopify.com/s/files/1/0431/3671/2861/files/midenojopod.pdf
    • https://cdn.shopify.com/s/files/1/0434/3519/6566/files/xubises.pdf
    • https://cdn.shopify.com/s/files/1/0432/9334/3899/files/mikodaweramazevetudu.pdf
    • https://cdn.shopify.com/s/files/1/0427/8072/1311/files/pilizaxiwevaf.pdf
    • https://cdn.shopify.com/s/files/1/0433/8833/8330/files/canon_rebel_t5_manual.pdf
    • https://cdn.shopify.com/s/files/1/0434/1373/3534/files/vezobibuvebasezun.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_off00006346.bin
e2a25d2d54d648f5a66e0fe76021c14d5a03c64622fae54f4280c8190c994336
pdf-font-stream PDF embedded font (sfnt) at offset 0x6346 5488 bytes
font_01_sfnt_off000075e3.bin
81529dc94adb7292159c498e5778d860f7306c61396904271da3a8ac658468d8
pdf-font-stream PDF embedded font (sfnt) at offset 0x75E3 10600 bytes