Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cfef81a8d7c7461…

MALICIOUS

PDF

49.9 KB Created: 2020-07-26 18:25:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ee70c7c797bca543514c365deb12e8d9 SHA-1: b1a848d371163a14693e98079fa8e17ba92e7bf3 SHA-256: 8cfef81a8d7c74615e7b11f6d18f73280a53fee46e091d84c33087688532fb9b
152 Risk Score

Malware Insights

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

The PDF file contains numerous embedded links, with a critical heuristic identifying it as a malicious redirector link farm. The primary malicious URL, 'https://ttraff.ru/pify?keyword=sample+letterhead+templates+word', is designed to redirect users to potentially harmful content. The document body, though heavily obfuscated, suggests a lure related to 'sample letterhead templates word', aligning with the observed link farm behavior. The ML classifier strongly supports the malicious nature of this PDF.

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=sample+letterhead+templates+word
    • http://files.theartofthesoloukulele.com/uploads/1/3/1/8/131856133/6116661.pdf
    • http://files.marketmovesmatt.com/uploads/1/3/0/8/130874629/nuvigure-bufagejiv.pdf
    • http://files.shawneecabinets.com/uploads/1/3/1/3/131382583/dulutorefopipaf.pdf
    • http://files.mark
    • https://cdn.shopify.com/s/files/1/0440/2210/4229/files/duxijemupevorazoxajadin.pdf
    • https://cdn.shopify.com/s/files/1/0431/1705/2053/files/21169463537.pdf
    • https://cdn.shopify.com/s/files/1/0430/6026/5117/files/87734261068.pdf
    • https://cdn.shopify.com/s/files/1/0431/4107/1016/files/60666148456.pdf
    • https://cdn.shopify.com/s/files/1/0427/9923/5228/files/49014124903.pdf
    • https://cdn.shopify.com/s/files/1/0437/2063/8632/files/49155575799.pdf
    • https://cdn.shopify.com/s/files/1/0435/9726/7112/files/bojizizujebopapiwogu.pdf
    • https://cdn.shopify.com/s/files/1/0432/3724/5086/files/4761465420.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/metegemekipezafekude.pdf
    • https://cdn.shopify.com/s/files/1/0435/2222/8376/files/94773730583.pdf
    • https://cdn.shopify.com/s/files/1/0430/6662/2105/files/detidutiwagunifukogizeva.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_off0000870c.bin
2ca3f08aacd1ab1a12e0178434a0fe7a5b5e24276058df1d6b726d272eed3773
pdf-font-stream PDF embedded font (sfnt) at offset 0x870C 5028 bytes
font_01_sfnt_off0000982d.bin
e8438febce0a1a53432f77b3c69643c7160a4f61e479fc1289daeafa485775c1
pdf-font-stream PDF embedded font (sfnt) at offset 0x982D 9940 bytes