Malicious PDF — malware analysis report

Static analysis result for SHA-256 caafcd85adbccce6…

MALICIOUS

PDF

84.1 KB Created: 2021-09-01 18:08:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: d38d7a6352a39ed240042e1891b67287 SHA-1: 604cca5dfb6ed45e54f7de756295ff8d3d91f639 SHA-256: caafcd85adbccce66c76080d573cbcbb3d31f83144f4c401b3ad9ef74e749f0a
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress upload directories, suggesting a link farm designed to manipulate search engine results or distribute malicious content. The ML classifier strongly indicated maliciousness, and the presence of multiple distinct hosts and disposable hosting patterns further supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://pistant.ru/uplcv?utm_term=how+to+pronounce+the+letter+r+in+english PDF link annotation
    • http://pillshop.ru/uimg/files/56094598024.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ca18fa7c99---sexaz.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/93805987976.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160944bcd40762---86733009080.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/161005f40af9af---31681619049.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/u03ghfft9oavnuitm44c2cqtl2/51223232102.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/e8286cd791b18a2afa4410c3fd3be3ba/vapuwadixugezagenokina.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609ac4c343f20---35891519509.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/708gekuteqdrd2qn845s8krsg7/48209910212.pdfIn PDF document text
    • http://wasserentkalkung.at/ckfinder/userfiles/files/viwanagigurover.pdfIn PDF document text
    • https://kham.vn/userfiles/file/nukiwevewilaginipokazuwef.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/wijijuwatotuzilogesuwafaj.pdfIn PDF document text
    • https://clubesolbra.com/uploads/files/50851306714.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160add20fb1fd1---dewafasowubi.pdfIn PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/bq4mske8ra6gmm8iqtuch7ctdh/nafifosisilodebijanukir.pdfIn PDF document text
    • https://getadoc.in/ckfinder/userfiles/files/totumegowalafojudoxunu.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6a0ae47d9a---85939874093.pdfIn PDF document text
    • http://gesundezellen.de/neu/userfiles/file/58840894244.pdfIn PDF document text
    • http://garderoba.sk/images/_file/18403842.pdfIn PDF document text
    • http://moto-bike.pl/userfiles/file/fedofewome.pdfIn PDF document text
    • http://xahscw.com/userfiles/file/12007200156.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fea64c1af9---kusivokoliv.pdfIn PDF document text
    • https://gazelletr.com/userfiles/files/ropodu.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_off0000de77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE77 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f689.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF689 19992 bytes
SHA-256: 5ac74e3df6cdabac3d09ce95e8ac506c730579ec08103b362736dfc82cab1660
font_02_sfnt_off00012aae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AAE 10668 bytes
SHA-256: e9b915d60ec416301a2b83d7b897a2322684dbac419a2456b7eb540b2c5fae74