Malicious PDF — malware analysis report

Static analysis result for SHA-256 81acae78361ab688…

MALICIOUS

PDF

86.9 KB Created: 2021-07-19 07:43:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: d8dc083e83b6252682192275c32a95f9 SHA-1: fb4e681283100670e25b4415652e55ad22ef7847 SHA-256: 81acae78361ab688b06f0ba9ab28e9ea0eb390a319d0317db2689c57611d387d
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm with numerous URLs pointing to compromised WordPress sites and disposable hosting, indicating an attempt to distribute malicious content or phish users. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link distribution scheme. No scripts were extracted, but the structure and URL patterns are indicative of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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 https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/db540577071e3247e991c908624a519f/dolexowanowawosu.pdf In PDF document text
    • http://www.mostex.sk/files/articles/file/jedozugamimatezexeza.pdfIn PDF document text
    • https://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/1l8dmi00bcs4ao6c6v1fpun501/96153054804.pdfIn PDF document text
    • http://kielcenoca.pl/files/file/fomoxopanebapagofisiliki.pdfIn PDF document text
    • http://titusrelay.com/clients/e/ef/ef304ccc03541e9e6382bef5f13b0a7d/File/vukadobuzenaz.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/gvenlbarf6afnfvfc91ekq9023/45423313219.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/160703a6782a30---77128287056.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c647b5f294---kavatanavumapemiretininaf.pdfIn PDF document text
    • https://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/0t8u0h40hf6vvfe8lg0cc12gaf/73002984777.pdfIn PDF document text
    • https://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/fc3a31c4284f5b4a020b0d645363226b/zavizapevugagapibikad.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/7dfcf3572e9c01a2f6a60b8cd8d5fa98/bodumebabizejagajiwev.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/c499913929b500b961ceb8eb228d5d0b/45979155335.pdfIn PDF document text
    • https://rotterdampools.com/contents//files/19580794076.pdfIn PDF document text
    • http://xn--kprq5pvqklteonubj6c.tw/CKEdit/upload/files/38576193518.pdfIn PDF document text
    • http://hagelkonzept.de/userfiles/file/nekapefod.pdfIn PDF document text
    • http://interstyle.org/content/xuploadimages/file/67522288491.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160c060005257f---fegap.pdfIn PDF document text
    • https://topupdana.com/contents//files/pumogikuzewa.pdfIn PDF document text
    • https://aokman-drive.com/d/files/6517733226.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16096f4f71afa0---raxupazixamezojojonisoti.pdfIn PDF document text
    • https://beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/3292eb53057c1ffa434a563db8271b9b/sogukimagerokomuvus.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/3a2bb095e9330c7378fc87f47375907f/togituramisajinelanujip.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/b58af0bafc896ecec9ab4d9adb3ce92b/8602005156.pdfIn PDF document text
    • https://invest.pl/userfiles/file/7974907064.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/ab5486fe3d0ede5450af462d393202a1/metajejojamewebijimid.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608ebceba98df---xuwuvadofunezifuzoxeno.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=heartburn+after+every+mealPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE64 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010676.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10676 18796 bytes
SHA-256: 487ca0454ec586f954266718bcdcf343fd8c378cbdf75207f3159c60ff25e679
font_02_sfnt_off00013692.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13692 10404 bytes
SHA-256: dfade582dca5a852777dea43d3728499b56885ad3285d81006460c1fe8385dce