Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa4b1137b3b20684…

MALICIOUS

PDF

35.1 KB Created: 2020-06-12 03:37:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: faa182e4c2d123e94aebeca9ff5f536d SHA-1: 88fc9f7987a63ac73b89ce114b94b72fd9956eb9 SHA-256: aa4b1137b3b2068498ef62f76630a28fe88873686297e2db09cfa70a6382fb55
94 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to other PDFs hosted on various domains. This behavior is indicative of a link farm or SEO spam campaign, designed to drive traffic to specific websites. The ML classifier strongly supports the malicious nature of this PDF. No scripts were extracted, and the document body is heavily obfuscated, but the presence of numerous external links is the primary indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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 http://xinquanxunwangtuijianeshibo.br3h.com/uploads/1/3/1/4/131409275/131409275.html#esl+worksheets+clothing
    • http://readytoadopt.ca/uploads/1/3/0/7/130775522/561401.pdf
    • http://flashtrailers.com/uploads/1/3/1/3/131398222/5c2f1de5e62310.pdf
    • http://greenvilleindoorkarting.com/uploads/1/3/0/7/130776065/jiroroturowosa.pdf
    • http://kittylomax.com/uploads/1/3/0/9/130969878/wagaded.pdf
    • http://redfernathenaeum.com/uploads/1/3/0/6/130640162/2ae0ba615a04.pdf
    • http://jason-davidson.co.uk/uploads/1/3/0/4/130483210/nivelizonozusiduse.pdf
    • http://aubae.com/uploads/1/3/0/4/130476192/wumexud.pdf
    • http://hostmaster.premierprescotthomes.com/uploads/1/3/0/5/130551654/344d5247d5b2fa.pdf
    • http://vuaaa.org/uploads/1/3/1/4/131453536/ratezopuzazen.pdf
    • http://mail.vaporhauschicago.com/uploads/1/3/0/6/130603741/8758703.pdf
    • http://selltogarrett.com/uploads/1/3/1/4/131437660/cc6ba1940d65d3f.pdf
    • http://orgonuts.com/uploads/1/3/0/4/130476313/0646be4b28.pdf
    • http://osvaldo-eportfolio.com/uploads/1/3/1/3/131383665/d163a.pdf
    • https://wodugodew847876
    • https://kaluferono394203149.files.wordpress.com/2020/06/mutusina.pdf
    • https://widuvupisofa124280327.files.wordpress.com/2020/06/bufuxejevipolizo.pdf
    • https://wodugodew84787651.files.wordpress.com/2020/06/zepitapurewotusiwerex.pdf
    • https://woxedafirewe.files.wordpress.com/2020/06/jofakupe.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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006278.bin
b3912f452d923a7fb49204b6e284c02d23a601dff0a4a48458beac00c995818a
pdf-font-stream PDF embedded font (sfnt) at offset 0x6278 8768 bytes