Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8209ebc02aa2aa7…

MALICIOUS

PDF

101.2 KB Created: 2021-07-02 02:47:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 516f729a324198960dd28cca9c50a77f SHA-1: 671e84543a448ba940632fabb836905e3a7990a8 SHA-256: f8209ebc02aa2aa7ab1444423ebe5f229a4c4958e42f39f96de6d8df6b07efb7
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, many of which point to compromised WordPress sites and appear to be part of a link farm. The ML classifier also flagged this PDF as malicious with high confidence. The primary purpose seems to be redirecting users to potentially malicious or SEO-abused content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/l2javi92cf4dnj4459tm7f2p2v/11568726441.pdf
    • http://innotack.com/userfiles/files/58209067208.pdf
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/4cdd7d606ee391aa9b2bed14cd4d8e27/petupasow.pdf
    • http://smithmaloney.com/clients/3/32/32eae1a42220421eddab78da2f55685d/File/3648779013.pdf
    • http://nc-israel.ru/upload/files/56783574272.pdf
    • http://sakem.org/userfiles/files/77877886255.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082f0d69d54c---26614517600.pdf
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/bd7bbf7f8ca9be39663b22fd5c838f1e/22297386096.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ca15b136b2---popajiwikakenofojo.pdf
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/d70e2891c3314a3e42d3e7e5f985c480/besod.pdf
    • https://www.surajinformatics.com/wp-content/plugins/super-forms/uploads/php/files/4d78cb877d98c2071cd047f0f2f13ecc/15327232123.pdf
    • http://bjbtrh.com/files/pic/file/94335936726.pdf
    • http://boothbayharborshipyard.com/userfiles/file/tomoxodis.pdf
    • http://cropscipublisher.com/files/upfiles/file/navowewejodatoro.pdf
    • http://a-kamen.com/userfiles/file/92802260505.pdf
    • https://egyiksem.hu/uploads/file/gaweniwetuvuto.pdf
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/38aadbe92f19bfc591bfa0a87114137f/77793607831.pdf
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a440582b368---98803291614.pdf
    • https://fullmagicweekend.com/ckfinder/userfiles/files/pakedaxibamivepokolepot.pdf
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099659f1b76b---40645145993.pdf
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/34gjpn1k2shte5uj7oromt0nmg/77027416053.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b487dea8a0c---48118741942.pdf
    • http://westtech1963.com/clients/d/d4/d4250bc21dcbbf02d7f9bc68df143add/File/futusuwameravikawavene.pdf
    • http://colleges-in-tamilnadu.com/FCKeditor/userfiles/file/bimaxodesifelizosigu.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=the+office+disco+cafe+songs
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001250e.bin
99e0fd4e3d866fe64fb33fc1d77e4189808aa1018d411203a70b66af1b327ae8
pdf-font-stream PDF embedded font (sfnt) at offset 0x1250E 10476 bytes
font_01_sfnt_off00013c92.bin
96ac825e035eca01c1740279f3b9b3e610a294657faadbdfee293af22e44afb3
pdf-font-stream PDF embedded font (sfnt) at offset 0x13C92 20288 bytes
font_02_sfnt_off00017085.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x17085 16792 bytes