Malicious PDF — malware analysis report

Static analysis result for SHA-256 a491fb7c8a835c34…

MALICIOUS

PDF

86.2 KB Created: 2021-07-20 06:33:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7d03d8f6d1b2729f024e9cc2c34484b7 SHA-1: c882e9de633f5e45098f46da801f3a43e31a1717 SHA-256: a491fb7c8a835c34b9df829017f09b1a1c5a688902c4db9c56e58b7a9dbac6a4
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to potentially compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristics and numerous URLs suggest a link farm designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.ecostroyservis.ru/File/porusakapefipugumuwitase.pdf
    • http://bielwod.com/userfiles/file/27097774436.pdf
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/aok8fu72bg4irjg12r78gf4oq1/lewunukudir.pdf
    • http://yournamebadges.com/withyourdog/cms_uploads/file/48971513497.pdf
    • https://rolcsi-bau.hu/userfiles/files/taxukumezarisivemuno.pdf
    • https://clove7.com/userfiles/file/15940023934.pdf
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/160835a451b370---87046183309.pdf
    • https://qqhanoman.com/contents//files/feratogoduvafasivelamew.pdf
    • http://falerisztika.hu/tmp/53016177182.pdf
    • http://wenxuezj.com/images/File/64966344039.pdf
    • https://aspaeng.com/files/image/files/61390510358.pdf
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/78mkr1e62235nc0eph8mr6tcq5/sovoz.pdf
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160ac1066695a1---45213013578.pdf
    • https://hophamthaibinh.com/upload/files/98156280.pdf
    • https://firsatpin.com/calisma2/files/uploads/67838554143.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081c4bcd3236---52912128422.pdf
    • https://galedo.cz/www/data/cms_files/files/53095493798.pdf
    • https://ph2020.org/ckfinder/userfiles/files/ratovawerunadanuvoxibew.pdf
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160bc2edfb2b34---diguzezexewudepufuli.pdf
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/6b175f19ed2848aefc137345b82fd0e3/katumedoturudufujol.pdf
    • https://dehayemek.net/upload/ckfinder/files/15304943527.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=stardew+valley+do+i+need+to+feed+chickens
    • 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_off0000ec46.bin
fa3b905412efed60acbbb0df5294d51a1536627299768a297eaee1f84357ea37
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC46 11008 bytes
font_01_sfnt_off000105d2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x105D2 16792 bytes
font_02_sfnt_off00011de4.bin
0232edb5458508eed53b23eece81ff4ff87ab75ce038a183756f01e54fe56d28
pdf-font-stream PDF embedded font (sfnt) at offset 0x11DE4 17328 bytes