Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad9f7653e88ff26a…

MALICIOUS

PDF

100.1 KB Created: 2021-10-04 14:56:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c8f3e624ef008d74f86415b9356943b2 SHA-1: 201bc68839f71edd67631aba613460877410aa06 SHA-256: ad9f7653e88ff26ab1c6a0842b9b61ac79ff81b5a605380e0ba81307dea843da
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to disposable hosting or compromised CMS uploads, characteristic of a link farm used for phishing or malware distribution. The presence of multiple PDF-specific heuristics related to URI and link farms further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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 https://crysiq.ru/uplcv?utm_term=why+does+my+female+puppy+hump+things
    • https://motelandratecuci.ro/userfiles/file/75213935612.pdf
    • http://zzquansu.cn/d/files/veliloguxigowunojuv.pdf
    • http://www.jindatunnel.com/up_files/file/japofawazetupo.pdf
    • http://fundacionecla.org/resources/original/file/tizulawuv.pdf
    • https://resulgame.com/calisma2/files/uploads/62349705961.pdf
    • http://snft.ro/media/file/suwavonejad.pdf
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613827bc4809e---fixasewo.pdf
    • http://angel-conference.org/upload_fck/file/2021-9-2/20210902125054556342.pdf
    • http://avision-italia.com/userfiles/files/76323307913.pdf
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/70s1l7q0eg66hg8t5m6bhurejk/digele.pdf
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/tl7pbnmqu27qbn2bvqbjgb6ap7/zafep.pdf
    • http://chip-chup.hu/upload/file/funasavogateramowof.pdf
    • http://re-media.ru/foto/ck/files/37692502932.pdf
    • http://dailymaydemtien.com/userfiles/files/5312368284.pdf
    • http://hwayinn.com/image/files/20210906_133325.pdf
    • http://tienphat.vn/imagesflashupload/file/47158901012.pdf
    • https://network-italia.it/file/2122279135.pdf
    • http://isotope3.pm-ural.com/uploads/files/16147143662.pdf
    • http://www.aunay-sous-auneau.fr/ckfinder/userfiles/files/birojikejujusazovos.pdf
    • http://cdkuysuujk.handysociality.com/upload/files/tilabonirove.pdf
    • http://mamnonkitty.com/webroot/img/posts/files/82149086028.pdf
    • http://gartenstadt-apotheke.com/userfiles/file/nefifosovajari.pdf
    • http://ecohort.com/userfiles/files/38600301704.pdf
    • http://dajia1.com/upfiles/editor/files/nederexidopel.pdf
    • http://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/sorapofazabapesesakepabol.pdf
    • http://aorganboys.handyfriendship.com/upload/files/13452754720.pdf
    • 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_off00012012.bin
0ba68adab4b13ea5c8e1075b67e324388e5ba7eb920dabf310ffa8a02f8603af
pdf-font-stream PDF embedded font (sfnt) at offset 0x12012 11052 bytes
font_01_sfnt_off0001396d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1396D 16792 bytes
font_02_sfnt_off0001517f.bin
6397dcaa4812e82a45366fafb178fff58425698e4196fb6e0945a44771e278db
pdf-font-stream PDF embedded font (sfnt) at offset 0x1517F 18880 bytes