Malicious PDF — malware analysis report

Static analysis result for SHA-256 db4773f39547d178…

MALICIOUS

PDF

85.9 KB Created: 2021-09-05 11:10:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b10d32743720f535c3b5f00134d19ca6 SHA-1: 39e04d71536de4108af2849b00fb702b538f2011 SHA-256: db4773f39547d178bb8644e9c3c2327bcc5a8d9bfbd095e00268a8f401919d3d
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to various domains, some of which are flagged as compromised CMS uploads. The primary purpose appears to be SEO manipulation or redirecting users to potentially malicious content hosted on these sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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.chp.pl/ckfinder/userfiles/files/baligarubexenubuwukapi.pdf In PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608101ed9f37b---16806166217.pdfIn PDF document text
    • https://thietbixanh.net/uploads/files/lufejudapasatet.pdfIn PDF document text
    • http://taihegas.com/filespath/files/20210809220440.pdfIn PDF document text
    • https://drddvichitra.com/userfiles/file/wakalesexidunu.pdfIn PDF document text
    • https://chmelo.hu/sites/default/files/file/53670881085.pdfIn PDF document text
    • http://suvagcentr.ru/userfiles/files/bimatogakupokitob.pdfIn PDF document text
    • https://bagstyle.uz/images/file/jagoberutul.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/e26vj8lblnmv1l8gb1i21j179a/78933746325.pdfIn PDF document text
    • https://xpress2.eu/ckfinder/userfiles/files/fepavu.pdfIn PDF document text
    • http://beepost.vn/upload/userfiles/files/xuwefisefavasoxatajuwe.pdfIn PDF document text
    • https://theptaynam.vn/upload/files/79934763474.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160f21a28e8cef---mugox.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1611e90a0d96ec---digoraxekumazilivozok.pdfIn PDF document text
    • http://iiiemjobs.com/FCK_Editor_Images/files/51558708423.pdfIn PDF document text
    • https://scavilecis.it/userfiles/file/lagatit.pdfIn PDF document text
    • https://anukulagrotech.com/userfiles/file/48044684265.pdfIn PDF document text
    • http://gildiamasterov.ru/userfiles/file/95102476919.pdfIn PDF document text
    • http://pphu-joanna.pl/fckpliki/file/51821719546.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/t8fkjkrhrpvkp6ni9aul33qc25/94406048965.pdfIn PDF document text
    • https://legouic-peinture.fr/userfiles/file/nonajokuzedub.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160d2141473238---56433030390.pdfIn PDF document text
    • http://jrmhandling.nl/upload/file/87648137876.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/16074b59e64561---fefubupebubaribogo.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/16076934d9144f---13263710779.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=2019+subaru+legacy+2.5i+premium+manualPDF 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_off0000e8b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000100c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100C4 17540 bytes
SHA-256: eb882178663c88fd153d1312232e0d1fcffdda7a4e415bc5c09b1be8a64ceaed
font_02_sfnt_off00012f06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F06 11420 bytes
SHA-256: ab130a7848bba1e0722470aeaec55c71d9d08b3cad6e8f1aae0ae0118446daef