Malicious PDF — malware analysis report

Static analysis result for SHA-256 31a8438771169cc8…

MALICIOUS

PDF

111.3 KB Created: 2021-06-27 06:32:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7b61aaa5c39ba5441f02619aacdce6b6 SHA-1: a8e82e258d2b8af0fe0940ca975b700cf838e427 SHA-256: 31a8438771169cc8b611f336df7167b20f87dacc24ffa869b302d077a6153f9e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains a link farm pointing to numerous URLs, many of which are hosted on compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns suggest it's designed to lure users into downloading further malicious content or visiting phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9868

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://jyotiacademicpress.org/uploads/file/kowapenonab.pdf
    • https://centrobrands.com/wp-content/plugins/super-forms/uploads/php/files/e008407e8d56297704dfbd10b91f4e50/99292855006.pdf
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c056611e10a---52680452490.pdf
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d322465d81---35125505759.pdf
    • https://thehideawayresortpattaya.com/userfiles/files/55120973852.pdf
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/871f7553fbbdb8bfb7f7ccf30020d09c/34858045539.pdf
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/gekoreze.pdf
    • http://matstravel.ru/userfiles/file/bedotipibujelozulolanepe.pdf
    • https://bouveau-consulting.com/userfiles/file/60168948868.pdf
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/8709ff4fe100528f33df2d12fec4dbc4/67760535235.pdf
    • http://munsusa.org/userfiles/file/20210522090026.pdf
    • http://abwcrainhwy.com/uploads/files/60783551382.pdf
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/4sh3o3sfrnc9j2tfaf0em99eqe/firazamudujik.pdf
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c35e5c2b851---5438508962.pdf
    • http://motivationandmomentum.net/ci/userfiles/files/xituxakuf.pdf
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/8003f31dff9bf3764bfc835a29e4edcb/wudutatigeli.pdf
    • https://naoshima-habitant.com/33568224138.pdf
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160886e1fbe81d---63599713833.pdf
    • http://micronforgacsolo.hu/UserFiles/file/85794220159.pdf
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/540ead056235b438ffa4aa91e0bbbab4/25199290255.pdf
    • http://mashtalkandil.com/userfiles/file/63714399740.pdf
    • https://atlastoursntravels.com/userfiles/file/takoluvevulefelaberefikog.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160852d0c4a61d---kalupebixazoxupenoda.pdf
    • http://forter.vn/hinhanh/file/39195791488.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=air+pollution+pdf+download
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013557.bin
3100b99ee842f19633d4e06e3fac7f49c5764b4cfe83a7d81727741c9dfd670f
pdf-font-stream PDF embedded font (sfnt) at offset 0x13557 18924 bytes
font_01_sfnt_off0001665d.bin
91b84d73967b48eeee4b9092a2a52cf35bc5c8fbee077f3ae03db331061bf9b9
pdf-font-stream PDF embedded font (sfnt) at offset 0x1665D 10356 bytes
font_02_sfnt_off00017de3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x17DE3 16792 bytes
font_03_sfnt_off000195f0.bin
6b6a5497a9e1492e93b688b5494b702ce4188a6b6cb3407b236273b4f3ce8cc0
pdf-font-stream PDF embedded font (sfnt) at offset 0x195F0 7628 bytes