Malicious PDF — malware analysis report

Static analysis result for SHA-256 a89ac1d937ba455c…

MALICIOUS

PDF

90.0 KB Created: 2021-09-21 04:18:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fdfb83105ebb9fc5c4729ae6dd89361c SHA-1: 8a76173d6ce3e8172d6329ab73c5f4dd28109214 SHA-256: a89ac1d937ba455c042eed1f5ab732388da71e6258f79505bca212c00a3a6a49
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external URIs and link farms, many pointing to compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://pretaporter-pegah.com/userfiles/file/pibesezuvikubo.pdf
    • https://ketex.com/trcgp/ckfinder/userfiles/files/pizenekugafezetilemago.pdf
    • https://b2b-intelligence.it/uploads/file/vewuvubodizidawowexaxep.pdf
    • http://pijntherapie.be/uploads/files/getutevijabojabizibumoxe.pdf
    • https://tabularasa.lv/sites/tabularasa/uploads/documents/files/19007080157.pdf
    • https://searchkar.com/ci/userfiles/files/88736612037.pdf
    • http://marmaraisg.com/images_upload/files/8607918074.pdf
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16133b9376b4f7---54461893541.pdf
    • http://xn--krmer-dnnebacke-1kb72b.de/files/file/batufuwasatov.pdf
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614420465f2bc---42681057045.pdf
    • https://anjingliar2.com/contents/files/legijewomike.pdf
    • http://bertoniamministrazione.it/bertoni/public/file/kikowuwitepowukosulim.pdf
    • https://www.frontieregypt.com/sites/all/libraries/ckfinder/userfiles/files/fejanafo.pdf
    • http://ylpqzl.com/ckfinder/userfiles/files/90487970344.pdf
    • http://ambvet-trefontane.eu/userfiles/files/50325633868.pdf
    • http://mywayrtk.org/userfiles/file/wolirel.pdf
    • http://0225674989.kad.tw/kads/ckfinder/userfiles/files/daluxovogurebu.pdf
    • http://dyglas.com/userData/board/file/mudiremogevireveg.pdf
    • http://zeci.nl/im/image/mibetagipezetonamelunogow.pdf
    • https://mongolia-volkslift.com/uploads/files/89398615117.pdf
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/161433cf7e141a---vefadariwenejezeb.pdf
    • http://capmar.eu/userfiles/file/buseboxufese.pdf
    • http://www.urbanwaterways.info/files/rorekumeruvun.pdf
    • https://franciscovalles.comtraining.cl/userfiles/files/gibolipumatesuwa.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=rain+app+android
    • 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_off0000f98d.bin
d6d15ea4833dd782f72ac335819e67a8c55767f61e9915a8840a75380dc31288
pdf-font-stream PDF embedded font (sfnt) at offset 0xF98D 19248 bytes
font_01_sfnt_off00012c73.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12C73 16792 bytes
font_02_sfnt_off00014489.bin
ca0efcc787662080d60de8b7e2fe94f6c41d7e551a0b5998ade36dbfe0b47b0c
pdf-font-stream PDF embedded font (sfnt) at offset 0x14489 9988 bytes