Malicious PDF — malware analysis report

Static analysis result for SHA-256 257c4276f3a476d6…

MALICIOUS

PDF

86.7 KB Created: 2021-08-15 09:51:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: dfcaca97b6019ad674bbfb7d9a08d455 SHA-1: 590206c05dbff7e2d346d5edcf4a40f9a974c158 SHA-256: 257c4276f3a476d6b39d6ce6028e80ff2ea3463a5b1280f3908fcfcb5d12b2b0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://mega-gold.com/userfiles/files/89221522027.pdf In PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/1608090800c236---wuzebewiteginosejofev.pdfIn PDF document text
    • http://biancoacolori.it/userfiles/files/somapoxod.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072893698c66---44607191863.pdfIn PDF document text
    • http://sintellect.ru/Repository/file/81939666914.pdfIn PDF document text
    • https://ssmavidiyar.com/public/content-images/files/pukovujixaxused.pdfIn PDF document text
    • http://sportsgarten.com/editorData/file/22438379411.pdfIn PDF document text
    • http://studioagronomoserragiotto.eu/userfiles/files/jarosapuzaxobujozepewup.pdfIn PDF document text
    • http://pune-india.info/userfiles/file/81430638253.pdfIn PDF document text
    • http://kingsauto-bar.com/js/upload/files/zekesopekujovuvumamop.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/47d5dae7ba8eb4c503bd8643a1e84f0b/33785490785.pdfIn PDF document text
    • http://janjoling.com/public/ckfinder/userfiles/files/pajemexelipuxitufufev.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/035f9b7baecdcceb60a86ab7fb003dac/70882977545.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160a24e121fb39---belorov.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610bd00212f02---nidizunetizo.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a40152f3773---52069700192.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf18c5d6cc---96213859977.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/g7ep5he61rh8nc9jjpe4i2vo45/manukavajifiwaxenago.pdfIn PDF document text
    • https://arerp.kr/data/file///34097082366.pdfIn PDF document text
    • http://auksozvynas.lt/userfiles/file/xagopokedibekatovab.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607864b1c2ce2---6996977573.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/78406b6a56d10f2a9b3e68f217df72a7/93169681791.pdfIn PDF document text
    • https://ibextrail.com/editor-images/70606593260.pdfIn PDF document text
    • http://orlickachata.cz/files/files/jasogizagixatezujalubu.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609acaef08a08---93124076499.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=how+do+i+turn+on+my+nordictrack+treadmillPDF 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_off0000ee9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE9E 16412 bytes
SHA-256: 733c511ce1b1e5bd8153d5e2e2983983fd0a3d6e0a6cf05a8c2e2e6ca5a664bf
font_01_sfnt_off00011905.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11905 10748 bytes
SHA-256: 47c0a981a0280f3c8e1b9a5d743f6efc436fb85e53e3fade51276000baf72ea1
font_02_sfnt_off000131bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1