Malicious PDF — malware analysis report

Static analysis result for SHA-256 b990bc055489307e…

MALICIOUS

PDF

89.1 KB Created: 2021-09-19 08:02:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 823ed657e613d75599195420383b6695 SHA-1: 941837a4c03068f29a32554a7608986ad8de3494 SHA-256: b990bc055489307e04f929eae47b653e004c9ddbcbbc95484f40d07756e8cbe6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to obscure the ultimate destination. The primary function appears to be directing users to potentially malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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.
  • 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://mixline.ru/img/lib/file/waxuguriruzibib.pdf In PDF document text
    • http://capitaloffice.pl/fotki/file/duramapudipibumopoxix.pdfIn PDF document text
    • https://bizimpin.com/calisma2/files/uploads/5050596528.pdfIn PDF document text
    • http://www.velkoobchod-man.eu/ckfinder/userfiles/files/dusamivudesumuf.pdfIn PDF document text
    • https://membermimpi.com/contents/files/12733865969.pdfIn PDF document text
    • http://ambvet-trefontane.eu/userfiles/files/midaremaritezofifej.pdfIn PDF document text
    • http://linkingpeople.info/userfiles/file/251402488.pdfIn PDF document text
    • http://lamelove-zakryti.cz/userfiles/file/javakadusiputod.pdfIn PDF document text
    • http://ossokahve.com/upload/file/xazekadebij.pdfIn PDF document text
    • http://tele-fonika.pl/upload/file/purelisewotepawu.pdfIn PDF document text
    • http://analhospital.net/file/files/37958572561.pdfIn PDF document text
    • http://phrabat.net/UserFiles/File/komenikurubifo.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/30cb64b2ed34b7971c66a40157810731/lolaranupijuk.pdfIn PDF document text
    • http://qdsenfeng.com/data/files/26584783560.pdfIn PDF document text
    • http://miryangpension.com/FileData/ckfinder/files/20210905_C03C5B85648949D1.pdfIn PDF document text
    • https://alatheir.com/atheirwsfiles/file/94450623376.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/477hgi8rv0s9h2gb7q5besc4u5/89934071873.pdfIn PDF document text
    • https://grupo-bahia-real-estate.com/ckfinder/userfiles/files/fodesatozabumowakofod.pdfIn PDF document text
    • http://vipdiler.ru/files/file/6257435140.pdfIn PDF document text
    • http://phutungtdc.com/upload/files/dafoxesewenik.pdfIn PDF document text
    • http://immopolignano.lu/images/gawosavolixibekewobotak.pdfIn PDF document text
    • http://sahamit.net/userfiles/file/1974503988.pdfIn PDF document text
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161436355c595c---vuxiwunazitodoleget.pdfIn PDF document text
    • https://kawanmto.com/contents/files/kuligej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=60fps+video+editor+androidPDF 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_off0000f136.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF136 19512 bytes
SHA-256: 2b1164051b920a33fd4128c5b2e16cc055f0783d099716b25918986f4007b380
font_01_sfnt_off00012429.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12429 10704 bytes
SHA-256: 0fbd7f95361c5aa1a1f7bc37494d747f20d71503c2f4bce06d80f6beea541d31
font_02_sfnt_off00013cdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CDC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1