Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6660531ffb93d1f…

MALICIOUS

PDF

41.3 KB Created: 2020-08-14 23:52:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c9413bb1f7ece164b1df90a2d4bb6d06 SHA-1: 774e3e4f5d1045ea0cbbf243436c843026d6ab97 SHA-256: b6660531ffb93d1fb05ca8c7d9e813467d4c799eca572741baf2c5dc7aad8f45
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a large number of embedded links, with one identified as a known malicious redirector. The ML classifier also strongly indicated maliciousness. The document body is heavily obfuscated, but the presence of numerous links suggests a link farm or phishing attempt designed to lead users to malicious content. The primary malicious IOC is the redirector URL.

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.com/wb?keyword=cpheeo%20manual%20water%20supply%20treatment%20pdf
    • http://files.allforkidscenter.com/uploads/1/3/0/7/130739212/raxisojip.pdf
    • http://xafizib.ritchiehair.com/uploads/1/3/1/0/131069934/bde0ed269bcf.pdf
    • http://files.macsnapshot.com/uploads/1/3/0/7/130740412/3151169.pdf
    • https://cdn.shopify.com/s/files/1/0431/9523/6509/files/36177233290.pdf
    • https://cdn.shopify.com/s/files/1/0430/9060/8285/files/love_stage_ep_1_english_sub.pdf
    • https://cdn.shopify.com/s/files/1/0434/8064/5782/files/67570864569.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/kuwuvovevikusezavufada.pdf
    • https://cdn.shopify.com/s/files/1/0433/0982/6213/files/rewinak.pdf
    • https://cdn.shopify.com/s/files/1/0431/9982/4032/files/fogawufud.pdf
    • https://cdn.shopify.com/s/files/1/0435/1967/2472/files/juzakesozilegonesi.pdf
    • https://cdn.shopify.com/s/files/1/0429/7365/9290/files/10333270052.pdf
    • https://cdn.shopify.com/s/files/1/0432/6404/9318/files/vodotute.pdf
    • https://cdn.shopify.com/s/files/1/0431/8763/4338/files/73402941130.pdf
    • https://cdn.shopify.com/s/files/1/0440/3914/3574/files/lisufokalatuwafesolilowan.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_off00006191.bin
6c83017869c9b4c641ee5488441e57010c49ea77073b618443584289b0adb694
pdf-font-stream PDF embedded font (sfnt) at offset 0x6191 5380 bytes
font_01_sfnt_off000073c6.bin
b6ca9414fe6d60c05e53f9fba8af64f819815c7805fa0fd72cef4d4cc1845560
pdf-font-stream PDF embedded font (sfnt) at offset 0x73C6 10688 bytes