Malicious PDF — malware analysis report

Static analysis result for SHA-256 79f1867019eb0a46…

MALICIOUS

PDF

49.6 KB Created: 2020-07-29 16:50:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1755c71b7967ce6ed60481f5542c9a65 SHA-1: 768eaff369c9d113f6ca5e92ffe1cbf660227c20 SHA-256: 79f1867019eb0a4666fbf1d471e239fa82d1f049d5f0fd5c5a0d09e59cf34366
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, forming a link farm, with the primary redirector pointing to a malicious URL. The document body, though heavily obfuscated, suggests a lure related to a 'work the system book pdf'. The ML classifier strongly indicated maliciousness, and the PDF structure itself was flagged for linking to known malicious redirectors and for being part of a link farm.

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=work+the+system+book+pdf
    • http://files.pragueguidebooks.com/uploads/1/3/2/6/132681632/4e65907699c.pdf
    • http://files.geraldinefirequeen.co.uk/uploads/1/3/0/8/130874120/2817852.pdf
    • http://files.tinpotleague.com/uploads/1/3/0/8/130814258/3258016.pdf
    • http://files.dontcrampourstyle.com/uploads/1/3/1/3/131380728/1651660.pdf
    • http://files.bobbeywillson.com/uploads/1/3/1/4/131482976/4851715.pdf
    • https://cdn.shopify.com/s/files/1/0430/6426/2818/files/ruregizodagolokedaxem.pdf
    • https://cdn.shopify.com/s/files/1/0432/9707/9460/files/68044891126.pdf
    • https://cdn.shopify.com/s/files/1/0437/2935/4903/files/bubajulotowotadila.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/94448736580.pdf
    • https://cdn.shopify.com/s/files/1/0438/5947/6630/files/gasilazoverobobagimubox.pdf
    • https://cdn.shopify.com/s/files/1/0431/5624/2581/files/38700495651.pdf
    • https://cdn.shopify.com/s/files/1/0430/8680/7201/files/90933496129.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/zaxolaxowixinetubosi.pdf
    • https://cdn.shopify.com/s/files/1/0431/8461/9680/files/27250515686.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/kumug.pdf
    • https://cdn.shopify.com/s/files/1/0432/4402/8059/files/7123358591.pdf
    • https://cdn.shopify.com/s/files/1/0437/7139/6257/files/wafajele.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_off00008512.bin
8e2665cb4eb9881b56ec6d43045076dd9e44b03b2e26814b610e7e1906480e14
pdf-font-stream PDF embedded font (sfnt) at offset 0x8512 4992 bytes
font_01_sfnt_off0000961d.bin
1ff961ece0aa4529635065bb848a2b6a33f91d45b61a2412ed6a69d350936dce
pdf-font-stream PDF embedded font (sfnt) at offset 0x961D 10232 bytes