Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f93fd1d6135f9e6…

MALICIOUS

PDF

94.5 KB Created: 2021-06-30 08:04:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dac5ac62763e39045b20ca22c9044f39 SHA-1: a02c26447b57f47fc41a943b7e9a1cc7be44387d SHA-256: 3f93fd1d6135f9e658b1cfdd8a92a7c08abaf17e9e402b2ef21d6d25ef72f1f7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution campaign, likely initiated via a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://krisoc.ru/uplcv?utm_term=broiled+skinless+chicken+breast
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160917ba0ee4df---bakadaninuxupasi.pdf
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082760be4f20---69737843500.pdf
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/0pkvn2m94uomvjr89f14pkid56/vigelavejukemuposuza.pdf
    • http://hytechplus.com/userfiles/file/tibukobekabivepabu.pdf
    • https://ises.ca/phpsites/vertical_living/uploads/file/98117652567.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/58f028243a716a34a37a7d66807b8e6c/fipapatu.pdf
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/96f3fe5d52a77702d57c827d5fc8a3b4/54537794458.pdf
    • http://www.aadhar-interior.com/userfiles/file/70809282837.pdf
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a64d676f134---libifosevukuxat.pdf
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/2f7db2ebabd7719a96f073f8834c9be1/gufalin.pdf
    • http://www.toptehnik.si/images/wegolepigitevomanevib.pdf
    • https://istanajpdua.com/contents//files/bexubajazobonowolomobeto.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/3de36ec57826202a054c40c4ac9009d5/minumonu.pdf
    • http://www.conectadoscomdeus.tv/arquivos/file/14028642068.pdf
    • https://riondene.ch/img/uploads/file/zulazadigi.pdf
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ca2226f072---89341492543.pdf
    • http://espacioschillout.es/images/admin/file/80429196948.pdf
    • https://sieuthimaytinhcu.vn/upload/files/fomawiruvusolipomuvaj.pdf
    • https://shidoremicrosys.com/media/85018884378.pdf
    • http://msslink.ru/userfiles/files/12831295188.pdf
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/a73c23aad70962dcfd5bc7e6161a3f80/32486516899.pdf
    • https://ferdavagnar.is/images/fck/file/86051909369.pdf
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/99728873c2268184d752f267d38d1966/94908835615.pdf
    • http://kyanite.tv/userfiles/file/76197321537.pdf
    • 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_off00010b70.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B70 16792 bytes
font_01_sfnt_off00012382.bin
c79e04f9b755d06cc13c96c76a09b6b6374a4422bebda59d07965815b6612249
pdf-font-stream PDF embedded font (sfnt) at offset 0x12382 17992 bytes
font_02_sfnt_off0001524c.bin
f1d66777da5fa9ddb904eee6e2bfe3cd9e5b4b38b1287d7347a5a3ef5bc11f9d
pdf-font-stream PDF embedded font (sfnt) at offset 0x1524C 10752 bytes