Malicious PDF — malware analysis report

Static analysis result for SHA-256 d81376531f4bb8d6…

MALICIOUS

PDF

86.0 KB Created: 2021-08-05 21:54:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 46cac5f1bf131cd36b1fa8906a69bf37 SHA-1: c8d57905b213c5bd63cd18e300957bae2e4b738e SHA-256: d81376531f4bb8d639a1dc79963b3ffa4acd6e181be00171df74b14227ee8033
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable domains, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the nature of the embedded links suggests a potential for delivering malicious payloads or phishing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://netron.pt/app/webroot/media/files/vofumamaxakajolevogeviwo.pdf In PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/p1d2tgklq14u5bks64hr2rb2t8/77501968866.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/godurisevalimotapa.pdfIn PDF document text
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/94dc542f0e28c13330b6ef665e2ccd54/87629278903.pdfIn PDF document text
    • http://emachn.com//data/attachment/file/mezomoma.pdfIn PDF document text
    • https://promise-land.com/upload/file/36267190017.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/vdpumkgd3q1357al2abe1iphc2/gusetuweboravusifotidafu.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160e42fd8c7191---potobububezabadabigus.pdfIn PDF document text
    • https://soba05.org/wp-content/plugins/super-forms/uploads/php/files/9208c0a888a3c45076fdc66b636d1df9/gimifarelirufaderoxufela.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/160736b4570781---mufuwofedasa.pdfIn PDF document text
    • http://bioterapiazabiegi.pl/obrazy/file/77441322918.pdfIn PDF document text
    • https://zold-kommando.hu/files/nagiw.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a605f1d8d70---buvunavez.pdfIn PDF document text
    • http://xn--k1akb4c.xn--p1ai/userfiles/file/18930337784.pdfIn PDF document text
    • http://gnatowski.pl/attachments/file/31851564729.pdfIn PDF document text
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/d60677799f8d0e95b68dbce956473229/6127693218.pdfIn PDF document text
    • http://kolkandkolkdesign.com/site/data/ws/files/pawomupetimafapenomu.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a20747c6594---tevujimagukazolorum.pdfIn PDF document text
    • https://ctsgroups.asia/images/file/16976117599.pdfIn PDF document text
    • http://cpspcb.com/uploads/files/simelusokatomub.pdfIn PDF document text
    • https://zifu-tech.com/app/webroot/userfiles/files/73717247219.pdfIn PDF document text
    • http://fabtur.ru/upload/files/50226698759.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/pamubimubulawepodijeze.pdfIn PDF document text
    • https://preprodpcb.com/userfiles/files/45277542361.pdfIn PDF document text
    • http://polskienarty.pl/data/aktualnosci_imgs/file/pejajuvizabasa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=half+marathon+running+plan+12+weeksPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e93b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE93B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001014d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1014D 17956 bytes
SHA-256: 1d875b722e1d0e782b7428293ed7c4d655bac3fbd7c96714d795e1539862a672
font_02_sfnt_off00012feb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FEB 11248 bytes
SHA-256: 8ff9f126cb59c39d826ee07a3aaff19d409ea16752cb3403f27a79d009cfffbb