Malicious PDF — malware analysis report

Static analysis result for SHA-256 e85d02c0458d1023…

MALICIOUS

PDF

41.6 KB Created: 2020-08-09 08:27:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 287acbf4b8db3e27121d9f79e59fce2b SHA-1: 891b0d0c82c24fe282d08fe30045636947cac45c SHA-256: e85d02c0458d102320c4b079ddc4aee3d329f52253206b2ed3393e6081343680
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to a redirector service (ttraff.ru) and then to other PDF files hosted on various domains. This behavior is indicative of a link farm designed to distribute malicious content or engage in SEO manipulation. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious redirector link.

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=doing+action+research+in+english+language+teaching+pdf
    • http://vemofi.downeynotarypublic.com/uploads/1/3/1/6/131636725/126488c81aabc5.pdf
    • http://files.sapphirestudio.co/uploads/1/3/1/4/131437535/6944951.pdf
    • http://mapumur.zionstone.co/uploads/1/3/1/4/131437308/donanijit.pdf
    • https://cdn.shopify.com/s/files/1/0440/7299/2918/files/23348654098.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/61047377128.pdf
    • https://cdn.shopify.com/s/files/1/0430/8716/7641/files/21926018711.pdf
    • https://cdn.shopify.com/s/files/1/0428/9137/8854/files/70903890381.pdf
    • https://cdn.shopify.com/s/files/1/0427/5562/1031/files/zobatutafediz.pdf
    • https://cdn.shopify.com/s/files/1/0432/5982/2243/files/67074404185.pdf
    • https://cdn.shopify.com/s/files/1/0429/9145/2314/files/85965564014.pdf
    • https://cdn.shopify.com/s/files/1/0434/4040/6684/files/53393227749.pdf
    • https://cdn.shopify.com/s/files/1/0433/7152/8344/files/49590007138.pdf
    • https://cdn.shopify.com/s/files/1/0434/5282/5750/files/44863264519.pdf
    • https://cdn.shopify.com/s/files/1/0429/7539/5993/files/81529033910.pdf
    • https://cdn.shopify.com/s/files/1/0429/4819/8556/files/54296748894.pdf
    • https://cdn.shopify.com/s/files/1/0431/5712/7336/files/fiat_test_study_guide.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_off00006351.bin
e95be3cde272a5d6077f6dcffe851b372bd6e5e17168b28279fef59be7773165
pdf-font-stream PDF embedded font (sfnt) at offset 0x6351 5416 bytes
font_01_sfnt_off000075c0.bin
ab6df20fa11cfa52c971b64ee1cb722d5b11ff61ee1a25a059748526a7a453cf
pdf-font-stream PDF embedded font (sfnt) at offset 0x75C0 10420 bytes