Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9a1ca77bde3f9e6…

MALICIOUS

PDF

95.7 KB Created: 2021-09-17 06:30:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2a34693829b2a6301a0e97b13e536746 SHA-1: 38f4c69d8d7081900c668b724de3fe531270d566 SHA-256: a9a1ca77bde3f9e6bee05180a256d1e498e06c1ed7b14c1c63e98275c8a52cc3
96 Risk Score

Malware Insights

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

The PDF contains numerous external links, with heuristics indicating a link farm pattern and the use of compromised CMS upload storage. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL analysis suggest the document is designed to lure users to malicious websites, potentially for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://dyccpharma.com/upload/files/65575373338.pdf In PDF document text
    • http://aow.infogestnet.it/ckfinder/userfiles/files/82074799136.pdfIn PDF document text
    • http://abwjefferson.com/uploads/files/ludisibuzi.pdfIn PDF document text
    • http://chinajessie.com/seadata/data/uploads/img/file/163113553490.pdfIn PDF document text
    • http://enkepharma.com/upload/files/52920593574.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/90880017764.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/50tflargdip7d11nh7ue3rludd/xetulirabewas.pdfIn PDF document text
    • https://osakaav.com/userfiles/files/66393013577.pdfIn PDF document text
    • https://goodluckfishing.com/ckfinder/userfiles/files/tusojirixodujozu.pdfIn PDF document text
    • https://francoisdaulte.com/ckfinder/userfiles/files/91262524979.pdfIn PDF document text
    • https://jxlmedu.com/file/files/20210916_195539.pdfIn PDF document text
    • http://naszymsladem.pl/upload/file/18627493801.pdfIn PDF document text
    • http://ux-school.ru/files/files/nisomuxofobi.pdfIn PDF document text
    • https://padservhosting.com/userfiles/file/30044250368.pdfIn PDF document text
    • https://superpackeg.com/userfiles/file/zezawawilawonugi.pdfIn PDF document text
    • http://wccflooring.com/userfiles/files/bevikotepis.pdfIn PDF document text
    • http://smolensk-bakaleya.ru/userfiles/file/21582217593.pdfIn PDF document text
    • http://tatvideo.ru/ckfinder/userfiles/files/jusobukavogozowubes.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/d065a88f8106898aec9a25ca1a9a1c9b/molipamowug.pdfIn PDF document text
    • https://cometsecurity.in/admin/userfiles/file/xadirireragugab.pdfIn PDF document text
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/861833906d727ac23b7c97da6ddb1d0f/66873873500.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/sutegexadukobusog.pdfIn PDF document text
    • http://mega.kz/media/upload/files/85428622839.pdfIn PDF document text
    • https://needlugs.com/userfiles/files/gedowor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=friends+reunion+watch+online+streamPDF 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_off00011033.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11033 10800 bytes
SHA-256: b793144023ddf34c45475e4a4084c9f1728f6eb498ee9d75b5656568e561299a
font_01_sfnt_off000128ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014101.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14101 18456 bytes
SHA-256: 6ae8bbcf0e0f0fe8650b1752d777d4ab110e458b461ccf72cdd266d8f79d53d3