Malicious PDF — malware analysis report

Static analysis result for SHA-256 16551848052c935a…

MALICIOUS

PDF

75.9 KB Created: 2021-09-08 02:08:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a09c98144d7da8a306ba36a984a8abb0 SHA-1: 9873519a19d7c5b9ca08d34104a37d7e0993da04 SHA-256: 16551848052c935a865ea8d40c6de9ecef8ddfd221dea1705179fd4053bfa07f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The presence of numerous links pointing to potentially compromised WordPress upload directories and disposable hosting suggests a link farm designed to obscure the ultimate destination, likely a phishing or malware distribution site. ClamAV detection and ML classification further 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 http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/16111e9cc032c0---sofagiperoxideju.pdf In PDF document text
    • http://englandmatchshirts.com/assets/file/xuzaminerojenon.pdfIn PDF document text
    • http://smingames.com/ckfinder/files/39860927604.pdfIn PDF document text
    • https://mmoxx.mn/userfiles/files/93662974928.pdfIn PDF document text
    • http://all-vehicle.net/js/upload/files/5260684444.pdfIn PDF document text
    • https://rainbowfurnitures.com/files/files/86308355986.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb2f31f194---22457059497.pdfIn PDF document text
    • http://xn--9w3b270a7kf.kr/data/editor/file/koxoruvijado.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/fcec2bf731a70107469db224b60c9abb/93122678312.pdfIn PDF document text
    • http://aj-freight.com/ckfinder/userfiles/files/93908542682.pdfIn PDF document text
    • http://tasarimak.net/ckfinder/userfiles/files/75145227460.pdfIn PDF document text
    • http://zaiger.ru/img/file/40109792906.pdfIn PDF document text
    • http://sungsam.net/userData/board/file/wadit.pdfIn PDF document text
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/34280589125.pdfIn PDF document text
    • https://aslplastic.com/ckfinder/userfiles/files/modokixas.pdfIn PDF document text
    • http://kleinschadenexperte.com/userfiles/file/fesorotimow.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/dabigejapel.pdfIn PDF document text
    • https://rockyshairsalon.com/wp-content/plugins/super-forms/uploads/php/files/5sj4jnqs15evthfhm5t2i0a6v7/70746209974.pdfIn PDF document text
    • http://poltinik.ru/userfiles/file/20694073819.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/100daaf85b3812e4ebf1c147734518aa/71195958438.pdfIn PDF document text
    • http://primaria-ciocirlia.ro/media/file/wodezevuviluzo.pdfIn PDF document text
    • http://pphu-joanna.pl/fckpliki/file/78256068601.pdfIn PDF document text
    • http://mlight.cz/archiv/file/besugefapebufev.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/cc3477378b6bdf6b07e16e6f1cba33ac/3279475978.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/7omehith7gvmrr8h2n6rup8gnp/zutuxob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=worksheet+grid+paperPDF 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_off0000c6db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6DB 16520 bytes
SHA-256: 1cc237d649377f94fb545f799b6c30a76fe6042876b237c2f644115921cf928a
font_01_sfnt_off0000f1b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B3 10604 bytes
SHA-256: 425ddb9ccfb3db861a006369c3c48bbb243643d2ac0b04d3b49995ea9dc65225
font_02_sfnt_off000109ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1