Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a4f1d212d63b6a3…

MALICIOUS

PDF

108.4 KB Created: 2021-07-02 18:58:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 04fe51e2dacc6e906943af1df0d998c4 SHA-1: e4d179f824370fc51a6afac4ba030d49a14116f8 SHA-256: 3a4f1d212d63b6a33db99c2a14ee8c9e1fd96005df52904b3dd82bd80e7e0891
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress upload directories, suggesting a link farm designed to host and distribute malicious content. The ML classifier also flagged this PDF as malicious with high confidence. While no scripts were extracted, the primary attack pattern involves luring users to external, potentially compromised, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9666

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 http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b94e5fea148---32511874894.pdf
    • https://pk-kuepfer.ch/ckfinder/userfiles/files/votanidemupopawoluw.pdf
    • https://chetanaus.org/bheru/uploadfiles/file/56044981093.pdf
    • http://teenaramainc.org/clients/875997/File/nazoxufopomuwujudafilaxos.pdf
    • http://dakmet.pl/upload/natinupatopobanudaj.pdf
    • https://wulf-sanitaer.de/wp-content/plugins/super-forms/uploads/php/files/m1rjkijkfb8ecld957erpvk5ff/92414651584.pdf
    • https://cleartunemonitors.com/ckfinder/userfiles/files/luzanizame.pdf
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae49af37138---41392696265.pdf
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/7562db5a95cf75f01a8c36a328594f52/midisubasifasema.pdf
    • http://gayaarchi.com/userfiles/file/20210602095536.pdf
    • https://himalayanthailand.com/image/upload/File/kikupetoterekakajuzewe.pdf
    • http://plafondchauffant.fr//img/user/file/70860742701.pdf
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b86a8e48321---setufuzezoziduwujo.pdf
    • http://eotp.info/sites/default/files/fck/file/nibobopozupanuretel.pdf
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/bivq761h2nrab9pkmqb7sa755q/7911504553.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be5c377be7a---6833217237.pdf
    • http://www.centralperdana.com/file/pogededopev.pdf
    • http://bpsstudio.hu/uploads/7307838876.pdf
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d961dac67d7---73999392425.pdf
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/d88ce2bc1830619d961506824ab6203c/31859430688.pdf
    • http://chistogood.ru/admin/ckfinder/userfiles/files/kiredixuxo.pdf
    • https://cytairtool.com/test/userfiles/file/20210626_34d74.pdf
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d3c0a29df36---10044525694.pdf
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/8b39f7d2104ba2fa72325597f38b2adc/vusaded.pdf
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/9ldiahb6bslhjn868fautd5u83/lakajonutunepoka.pdf
    • https://audit-advisers.com/userfiles/file/88660632869.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=equation+of+normal+to+parabola+in+slope+form
    • 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_off00012693.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12693 16792 bytes
font_01_sfnt_off00013ea5.bin
c7fde37a9dbbbb651e7f5baadd3fafc0d96579409464b0697d04d20256f36395
pdf-font-stream PDF embedded font (sfnt) at offset 0x13EA5 19548 bytes
font_02_sfnt_off00017359.bin
dcfb2b2462e5f74e3c42b86cab1f04e094b4e3b40f4ae133fb188fe13f8611d5
pdf-font-stream PDF embedded font (sfnt) at offset 0x17359 10888 bytes
font_03_sfnt_off00018c43.bin
450eea5fc67953cc3bdc764260aa6f1739571c17331c9588074966c3dbef4c6c
pdf-font-stream PDF embedded font (sfnt) at offset 0x18C43 16088 bytes