Malicious PDF — malware analysis report

Static analysis result for SHA-256 0b4f70651c9f8867…

MALICIOUS

PDF

96.4 KB Created: 2021-08-19 04:37:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: bb1530967d5a32a597340cdbe9b35b71 SHA-1: 2e6a0a709dba218b2c8d251103632758aefb9ae1 SHA-256: 0b4f70651c9f88671086ed1d8a6741c59f6f31fb6ff290a613a31b1e7e3fa182
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, likely to redirect users to malicious content or phishing sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, suggesting a tactic to distribute malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607569b28be07---64759054485.pdf In PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/16108e9e7b54a9---83436923434.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e4d6729703a27dfa134c59a596ad07db/43431189546.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609ecd4378492---modileregapo.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/8ia5o68vad0301m6b6872oevnh/55641167294.pdfIn PDF document text
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/5e40fa892278712c670bc8e6dbc701d4/bosexolijididelob.pdfIn PDF document text
    • http://marsalanoleggio.it/userfiles/files/99070094635.pdfIn PDF document text
    • http://caf-ljubljana.si/docs/48006407868.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/ldedimc1oh0gvv58mgt0c6si06/45181108443.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/d4207a36399852ed618ce16cdee63292/79251399953.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/mibewa.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609853928d54c---58709655282.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/karer4q2q3k28jmqmspnu5c552/wefakiwif.pdfIn PDF document text
    • https://roadtoring.com/wp-content/plugins/super-forms/uploads/php/files/e46e9169e66798ac7d8a7db3c6cb6d29/zofebigorevufodog.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/b8aebac2bc819e8fc7ba4350c53e3e3a/bibajetinuwivez.pdfIn PDF document text
    • https://uniqrelation.com/userfiles/file/70003027630.pdfIn PDF document text
    • https://elperrocallejero.info/ckfinder/files/tagadisifemesajokegupef.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ba04650e807---6375795341.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071578946e4a---wigazajuwenujerajewin.pdfIn PDF document text
    • http://littlepearlspublishing.in/data/eimages/file/47923934587.pdfIn PDF document text
    • http://vtvxm.vn/userfiles/file/pexadazijam.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609117c598ca9---winewanuk.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/95cb27c9eaa6092a6d50aac9e7092c65/siwafawikibujo.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/com7mbl8432kdd4onlbu98krvn/44831541609.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=can+you+bring+a+backpack+as+a+personal+item+on+allegiantPDF 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_off000110e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110E8 17392 bytes
SHA-256: 6254390ac92fe9508b1ada073dd3ca71f2e01ece3b3aaf198e4ac18d188fa398
font_01_sfnt_off00013e95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E95 11196 bytes
SHA-256: fce945d563bdc342a976b6a34c252616bd78116ea141579b95656c4ce12cd886
font_02_sfnt_off000158a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x158A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1