Malicious PDF — malware analysis report

Static analysis result for SHA-256 df53f5afc0d09317…

MALICIOUS

PDF

89.8 KB Created: 2021-06-27 06:25:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 722d4e4f7465e8f562111b69898cbc23 SHA-1: beb679eec540fad7d40eee83f26c49b28681f674 SHA-256: df53f5afc0d0931769328e94c8517c2468c0f4f0812cc92340dafaefe2bbffda
96 Risk Score

Malware Insights

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

The sample is a PDF document identified as malicious by an ML classifier. It contains numerous embedded URLs, many of which point to compromised WordPress sites hosting other PDF files. This suggests a link farm designed to redirect users to potentially malicious content, likely for phishing or malware distribution. The presence of multiple compromised CMS upload links further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/2erngrd3q66p2ih8vfapfv6526/40792456616.pdf
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/aba81ab5ee99c67b4f53547c4d0a9c02/kijujimolomowijenugej.pdf
    • http://gloucesterclassof81.com/clients/23558/File/683097041.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/16078244a95f12---pusipoda.pdf
    • https://stegopackaging.com/wp-content/plugins/super-forms/uploads/php/files/3cupkn5cnifvhgqoa4u65paa9v/8319448268.pdf
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bff48b09579---nidozilifa.pdf
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607b07800eae8---bitijoxufitaz.pdf
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160842e3d71d3a---jesuweluvazi.pdf
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160842ae84da74---wevuz.pdf
    • https://toppelletmachine.com/d/files/76974604342.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c5323aac14a---ridikuwewaxulo.pdf
    • https://dijitalsanat.link/upload/files/wikifolotomewajibumas.pdf
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//zuzafelatizimukepotere.pdf
    • https://pbchistoryonline.org/uploads/file/kolaxovuwon.pdf
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160728c2f304a0---jediwojinowe.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c96e2681055---25714990144.pdf
    • https://aimhc.com/userfiles/file/lirugujogibes.pdf
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/160795062c5f4a---75732539120.pdf
    • https://lesfeesdelhetre.fr/upload/files/57409664901.pdf
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcc29c64549---60110943307.pdf
    • https://1877painters.com/FCKeditor/file/povev.pdf
    • http://oprfhs70.com/clients/879438/File/1823892137.pdf
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acbcadc9704---bimoguriwate.pdf
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16075faa13e22e---gikopubakidafowenupofu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=cbse+class+7+social+science+mcq+with+answers
    • 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_off0000f8ee.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8EE 16792 bytes
font_01_sfnt_off00011100.bin
b8e4ec010fb6780deb1d06720e06aa4408f0af6185dcc6e231701a504d9c8d93
pdf-font-stream PDF embedded font (sfnt) at offset 0x11100 17384 bytes
font_02_sfnt_off00013e94.bin
c19b2272deddda85e6e8935c279ec4dd36391bbcd5627beb4ca57984e9d2e255
pdf-font-stream PDF embedded font (sfnt) at offset 0x13E94 10948 bytes