Malicious PDF — malware analysis report

Static analysis result for SHA-256 b902723c65c0fd35…

MALICIOUS

PDF

76.3 KB Created: 2021-09-26 10:47:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1b4132c4ae0e1778a0bfa65cbc6cca3c SHA-1: 35547fbc53a6df94e680cb506fa65658d7a09c92 SHA-256: b902723c65c0fd35cdb097af48818f2cb9a5dec5ea86da7ac2c047818560b76b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF containing an embedded JavaScript stream and a large number of URLs. Several heuristics indicate that the PDF is acting as a link farm, with many links pointing to compromised WordPress upload directories. This suggests the document is designed to redirect users to malicious content or download further malware. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/1inljm40urjgjjtrcttv02f6jc/kebuvakekek.pdf In PDF document text
    • http://www.celso.org/download/jofijugupifopenexisero.pdfIn PDF document text
    • http://amuseonline.com/absite/userfiles/file/nunewepojugetome.pdfIn PDF document text
    • http://brenno-tojestto.pl/userfiles/file/zaborozilikefotojulilumum.pdfIn PDF document text
    • http://rtm-plus.com/ckfinder/userfiles/files/91310177424.pdfIn PDF document text
    • http://hzyixiangchem.com/upload/files/pidobulexinevegebuv.pdfIn PDF document text
    • http://ipoz.pl/userfiles/file/10913754309.pdfIn PDF document text
    • http://www.palmettoexpresslanes.com/system/js/back/ckfinder/userfiles/files/vikesepisekemopegozo.pdfIn PDF document text
    • https://linhngapt.vn/upload/files/vusemalinovadubi.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16138bbad47010---nuletuvaxosusibi.pdfIn PDF document text
    • http://portakalweb.net/home/portakal/public_html/ckfinder/userfiles/files/70804342659.pdfIn PDF document text
    • http://stolizstekla.ru/userfiles/file/tovamujivodamorigejavu.pdfIn PDF document text
    • http://mos-craciun-inchiriere.ro/fckfiles/file/davibinodisukaseru.pdfIn PDF document text
    • http://professional-tuner.at/uploaded/file/fupirafadidexifolosapot.pdfIn PDF document text
    • http://arenda-v-novosibirske.ru/ckfinder/userfiles/files/likawemiwovezetabomamexa.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16132669346ef0---kogiv.pdfIn PDF document text
    • https://kueapem.com/contents/files/12725239358.pdfIn PDF document text
    • https://semangkamerah.com/contents/files/dasuxedaxoxos.pdfIn PDF document text
    • http://bud-drog.pl/userfiles/file/11411899705.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16148e54edfeee---36155199788.pdfIn PDF document text
    • http://studioaeditecne.it/userfiles/file/81871240325.pdfIn PDF document text
    • http://anipetkingdom.com/webroot/img/files/64974016819.pdfIn PDF document text
    • https://pakianco.ir/data/image/uploads/news/files/duwaledirebimesizubo.pdfIn PDF document text
    • http://xn--80aafjbaeihgganggf9ajkncugh2a.xn--p1ai/pict/file/27921149995.pdfIn PDF document text
    • https://iamtimeshare.com/userfiles/file/12669914905.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=quadratic+equation+solution+by+completing+the+squarePDF 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_off0000bd83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD83 19704 bytes
SHA-256: 5b5c2f0af7dee08ffdc82e6e9bcf8569326cd71659d3eee41d5fa2b4c297e240
font_01_sfnt_off0000f073.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF073 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001088a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1088A 11520 bytes
SHA-256: 4e4db3af8863da36a00baa83fdac938f35290e11e7dfa78d074f8e27675eecd1