Malicious PDF — malware analysis report

Static analysis result for SHA-256 11b1b53682435ae1…

MALICIOUS

PDF

79.1 KB Created: 2021-08-31 06:38:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 5049b29ae95f6cecb65b75e4235d167f SHA-1: 3f4ce2cefcfd2da3dfc16f45a26a78edd5942065 SHA-256: 11b1b53682435ae1074903855d67150333739b820b2e7938d6d1dd01e0255074
96 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, many of which point to compromised WordPress sites. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest this PDF is part of a link farm designed to manipulate search engine results or redirect users to malicious content. No scripts were extracted, but the extensive use of external links is a strong indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://synerhu.ru/uplcv?utm_term=what+does+imk+mean+in+a+text PDF link annotation
    • https://floridaholidayplanner.com/wp-content/plugins/super-forms/uploads/php/files/507adc4e4edde40da5028898a7ac5c46/89948250423.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/6l1gbuskrl7fvjc0r344db901o/gadiw.pdfIn PDF document text
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/b4c0eacf2c7ac221e047c80f82a14ff7/80959585810.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/7fc205aaeb890acd22784295f9505cd2/43732045369.pdfIn PDF document text
    • http://sahrugs.com/userfiles/file/3973584684.pdfIn PDF document text
    • http://blpest.com/UserFiles/file/30798390487.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/6b76341095c37384e093beaa0d07e30d/19897282528.pdfIn PDF document text
    • http://twinmd.ru/userfiles/file/60760411879.pdfIn PDF document text
    • http://sbcnepal.com/images/file/zasizuli.pdfIn PDF document text
    • https://oklogistic.lv/upload/file/pesili.pdfIn PDF document text
    • http://hajnysport.cz/FCK_userfiles/file/11076282271.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d0c371e31---kowirokepepekuranejotowe.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/84069880584.pdfIn PDF document text
    • http://massageindex.nl/images/uploads/30356670676.pdfIn PDF document text
    • https://rajakeempat.com/contents/files/munaketoxemisegivajewesu.pdfIn PDF document text
    • http://www.hangmandigital.com/files/file/66759603809.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16087b5737b318---zetedusejuzawudexovo.pdfIn PDF document text
    • http://losmarinoslanzarote.com/marinarubicon/admin/file/kosikodo.pdfIn PDF document text
    • https://seerupit.dk/assens/file/zomuwuzox.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d28a93b6588---muxubulifodap.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7115f3ea57---xajosomiguvikorusu.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/f1120dbc572dfd79640cef7781add065/rinasamugowo.pdfIn PDF document text
    • https://klubkanine.com/home/klub/public_html/ckfinder/userfiles/files/xijumigeriseraluxofaja.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/07a8b4f958dc4b46140de93c5220b15e/38911610291.pdfIn PDF document text
    • 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_off0000ceb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEB5 10552 bytes
SHA-256: 3695ea4c42ae2cb29d8c28b1a4ba9dcf0480e6dc1ac86ce0aae4f72e57e5700b
font_01_sfnt_off0000e69b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE69B 18452 bytes
SHA-256: 534538253dab120078be36f0fa762013c767e7c43b9022da7febba8abce954af
font_02_sfnt_off00011650.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11650 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1