Malicious PDF — malware analysis report

Static analysis result for SHA-256 454fe4c765c2103a…

MALICIOUS

PDF

80.8 KB Created: 2021-09-18 16:43:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 31087cb7abd8cff0a48b7c59f25d9a52 SHA-1: 6a0b08ec77b25571afa3b4064b7b91cc5c85de6b SHA-256: 454fe4c765c2103a635dfae160369d8ad78bb3c3898c094b391c0cdb9f4fc0e5
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. The presence of a link farm on potentially compromised or disposable hosting, combined with ClamAV's detection of 'Pdf.Phishing.Trojan', strongly indicates a phishing or malware distribution campaign. The embedded JavaScript likely serves to initiate the malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 7

  • 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.
  • 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://sentralperdana.com/file/81279147628.pdf
    • http://zl369.net/userfiles/file/23073597517.pdf
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16140cddc43aa3---83777380372.pdf
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/jelasenazuta.pdf
    • http://xn--hh0b97d8is16e.com/userData/board/file/xadugeruwafebo.pdf
    • https://nordiskvillaventilation.dk/userfiles/file/5416947248.pdf
    • https://arbormaster.us/uploads/files/mivukanukagive.pdf
    • http://fgosvo.ru/files/files/7102611066.pdf
    • http://trustarshida.co/cache/fck_files/file/14358622253.pdf
    • https://fratellifurloni.it/file/14542309550.pdf
    • http://pillshop.ru/uimg/files/tenitiw.pdf
    • http://to-kajihan.net/js/upload/files/sixevuxapunufumewiseseba.pdf
    • http://avstralianature.ru/ckfinder/userfiles/files/loxizixamaba.pdf
    • https://erdemlerkoleji.com/resimler/files/disabov.pdf
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/55fe39e15afacc9cf798222807c9903e/rulidu.pdf
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411b1c3d673---dexajulizekunebilomolenoz.pdf
    • http://antitumor.org/filespath/files/20210903005254.pdf
    • https://pharma-tools.pl/galeria/file/248723466.pdf
    • https://armature.ir/cache/fck_files/file/tofesiwonovakawefa.pdf
    • https://pcparts.fr/ckfinder/userfiles/files/polenokozajizos.pdf
    • http://refpecsbelvaros.hu/kepek/files/46823554296.pdf
    • http://cka-shiba.com/ckfinder/userfiles/files/bikobuviriwupate.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=latest+android+music+player
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d913.bin
fdaff542b2ddf23e10f45d6cf61116abca5617b081242f9fdd9b925836b7b60d
pdf-font-stream PDF embedded font (sfnt) at offset 0xD913 10848 bytes
font_01_sfnt_off0000f221.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF221 16792 bytes
font_02_sfnt_off00010a33.bin
ace20b054f7ace70903dc423a636032e791f836abe1510e49cd4c47107d2bc6d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A33 17068 bytes