Malicious PDF — malware analysis report

Static analysis result for SHA-256 83850d825b891ab6…

MALICIOUS

PDF

32.9 KB Created: 2020-08-08 13:14:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e19d093a547a2fd4f738f73bd73e4afd SHA-1: 30d91684e97b8dced8037614338ed7cf084c69f8 SHA-256: 83850d825b891ab6f9a7b7d7521fbca9c75d0a1aaf3abc116f1850dc1dd4d778
154 Risk Score

Malware Insights

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

The PDF contains embedded links that redirect to malicious infrastructure, specifically identified by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The document body, though partially obfuscated, contains text suggesting it is a 'revision kit' for an audit, which is a common lure for phishing or malware delivery. The ML classifier strongly indicates maliciousness, and the presence of numerous external links, many pointing to Shopify domains hosting PDFs, suggests a link farm used for SEO poisoning or distributing further malicious content.

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/wb?keyword=acca%20f8%20audit%20and%20assurance%20revision%20kit%20pdf
    • http://files.alpost119.org/uploads/1/3/2/7/132740399/a6dba498.pdf
    • http://files.mayaolsonphotography.com/uploads/1/3/1/4/131454034/fofozu.pdf
    • http://files.therandytravisfoundation.org/uploads/1/3/2/7/132740485/guvik_tijokoko.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0429/4852/6246/files/66040013799.pdf
    • https://cdn.shopify.com/s/files/1/0431/7318/3643/files/nerasafuromokijuxexexiwa.pdf
    • https://cdn.shopify.com/s/files/1/0432/3108/4708/files/kadovusod.pdf
    • https://cdn.shopify.com/s/files/1/0434/1815/7221/files/lobo_vs_wolverine.pdf
    • https://cdn.shopify.com/s/files/1/0433/7831/1326/files/d3dx9_._26._dll.pdf
    • https://cdn.shopify.com/s/files/1/0428/6971/9199/files/86864551619.pdf
    • https://cdn.shopify.com/s/files/1/0437/1188/9562/files/worebiwirorof.pdf
    • https://cdn.shopify.com/s/files/1/0431/7852/4832/files/42327307670.pdf
    • https://cdn.shopify.com/s/files/1/0433/4944/2715/files/pdfill_free_tools.pdf
    • https://cdn.shopify.com/s/files/1/0447/8458/2813/files/aberturas_de_xadrez_para_leigos_james_eade.pdf
    • https://cdn.shopify.com/s/files/1/0438/3621/1362/files/chiltons_repair_manual.pdf
    • https://cdn.shopify.com/s/files/1/0434/4718/9670/files/setosovuro.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_off000041ec.bin
fdb30b59b09723ad7744d982037a9f12d1412408f6a54e36b060a275d172b309		 pdf-font-stream PDF embedded font (sfnt) at offset 0x41EC 5424 bytes
font_01_sfnt_off00005481.bin
1168bacd5bfcfa9821101981642fa0b37d2912f8c08b777d56b4d668f2c2dc2d		 pdf-font-stream PDF embedded font (sfnt) at offset 0x5481 10508 bytes

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