Malicious PDF — malware analysis report

Static analysis result for SHA-256 83e92ff159d36a47…

MALICIOUS

PDF

77.9 KB Created: 2021-09-03 13:52:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 66141b0311758cd7881e8c56ea3762e6 SHA-1: b621a6d0e6f13b2543709c9402c0b000ef43c5e5 SHA-256: 83e92ff159d36a47de6887ee0863109251f823afcd52ae79f4ef8577582dc931
164 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains a link farm pointing to numerous PDF files hosted on potentially compromised or disposable domains, suggesting an attempt to distribute malware or phishing content. The presence of a 'download button' heuristic further supports a lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://dinskayarealty.ru/media/file/pisaziwakomimegejup.pdf
    • https://medicentrumnz.eu/medicentrum/files/file/punuta.pdf
    • http://ayhancevik.com/images_upload/files/94080394348.pdf
    • https://rtvpuls.com/ckfinder/userfiles/files/kimelarefamaxuka.pdf
    • http://sbsinternationalschool.org/sbsisnew/userfiles/file/86522313402.pdf
    • https://shopinhome.com/ci/userfiles/files/28401682406.pdf
    • http://amoy-art.com/Upload/file/wexedupibuwoti.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/rbf9bjh9rtdr0dfpvkkp5kibmn/nopejotegasuvemugexiwu.pdf
    • http://mamaskitchenorder.com/uploads/files/16721602825.pdf
    • http://syuncyoku.jp/upload/file/59357982216.pdf
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607159e743abe---wojukinuwoletef.pdf
    • http://www.swaving-stalinrichting.nl/ckfinder/userfiles/files/kamawuxaf.pdf
    • http://kamnitikamini.si/upload/files/26395448872.pdf
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/c223e6eb80766e2a26f17abec185b925/rifadofo.pdf
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/3902f56cb50f65ab22b7b8d6f44ae1aa/mifikugezesupaf.pdf
    • http://kibbkw.com/uploads/file/dokujabev.pdf
    • http://kxqcgs.net/filespath/files/20210831010810.pdf
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/047d76c8f7bf0976f4519c974c2b7935/zuteronawiwudet.pdf
    • http://mini-garden.ru/userfiles/file/41068508643.pdf
    • http://harryreichert.de/uploaded_pics/News/file/zevokozon.pdf
    • http://raylutickenterprises.com/userfiles/files/vudox.pdf
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/161313d3c3313b---67752623603.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=first+grade+sight+word+worksheets
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • 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_off0000d1ca.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD1CA 16792 bytes
font_01_sfnt_off0000e9e1.bin
d8763e332791dfb4223c3979df2f855163aea9c471ff07e89cafeae4e1dff9fd
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9E1 10532 bytes
font_02_sfnt_off000101de.bin
702e5ff05dcf6b83b5c96a4a6f37c35fc11d0a35d2f1c1a7ede531ceaad4b8de
pdf-font-stream PDF embedded font (sfnt) at offset 0x101DE 17948 bytes