Malicious PDF — malware analysis report

Static analysis result for SHA-256 af8b3403c2c2b7b6…

MALICIOUS

PDF

83.7 KB Created: 2021-08-15 13:03:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: b299614e15222ac985ee229f158ea596 SHA-1: d5a651ce40001d8ec5d40574b12a259686eec438 SHA-256: af8b3403c2c2b7b6e5de4bc90665f763ff326127ca0e82c0b68f5f89e390f4c9
156 Risk Score

Malware Insights

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

The sample was identified as malicious by a ClamAV signature and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting, suggesting a phishing or redirection scheme. The presence of multiple PDF link farm heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://anvlaw.com/userfiles/file/83523391420.pdf In PDF document text
    • http://csc028.com/userfiles/file/20210614120445_pag1z6.pdfIn PDF document text
    • https://machinex-machines.com/UserFiles/File/7941311025.pdfIn PDF document text
    • https://infrastone.com/userfiles/files/11149607723.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/36c6a35673fa76b8ffa05a0cdf302d69/67163493031.pdfIn PDF document text
    • https://n-zvuk.ru/upload/file/75799953769.pdfIn PDF document text
    • https://korzayithalat.com/spot/admin/fckeditor/userfiles/file/demarasitefamixolikosip.pdfIn PDF document text
    • http://inwama4.vn/webroot/img/files/vizikawasedad.pdfIn PDF document text
    • http://vnos.vn/app/webroot/uploads/files/zuvawovinuferubafib.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/nofolajitozupidori.pdfIn PDF document text
    • http://giasuthanhdat.vn/Images_upload/files/rerisajikuwomap.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160d87c0c0320b---lajereg.pdfIn PDF document text
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/0b7922e7a5c44ec109a702f44f95020a/62512378200.pdfIn PDF document text
    • http://jx4d.com/userfiles/file/nosisivipagagepomagugel.pdfIn PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/3aa925fad79c8ef69c48d4fe5448b93b/59826891420.pdfIn PDF document text
    • http://www.multigacos.com/admin/uploaded/fck/file/56914092619.pdfIn PDF document text
    • https://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/7krjsenar01csu17ivfbs1i5l4/79923883740.pdfIn PDF document text
    • http://chretkinia.pl/userfiles/file/fuwirewirawaxonomago.pdfIn PDF document text
    • http://abovomedia.hu/_user/file/36233105595.pdfIn PDF document text
    • https://bawwabatrizq.com/userfiles/file/6759688021.pdfIn PDF document text
    • http://kapsalonvogue.nl/files/file/jorikanelijibuvezupuziz.pdfIn PDF document text
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/kr3oqga1mgjab9ch7nnjlhc566/84951155657.pdfIn PDF document text
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607cccfd3236a---83985771750.pdfIn PDF document text
    • http://www.xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/19157348561.pdfIn PDF document text
    • http://huerural.com/uploads/image/files/85718979476.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=hra+child+care+application+nycPDF 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_off0000e2d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2D6 10548 bytes
SHA-256: 999cd0664c2322258c950b174255e74214d5c685f23260933e12e165e784d502
font_01_sfnt_off0000fabf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFABF 17128 bytes
SHA-256: f08fa4ddf4d8e387176d7192d15f805191e56ab2a636d1a9e1e6c17cd00dba29
font_02_sfnt_off000127ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1