Malicious PDF — malware analysis report

Static analysis result for SHA-256 af5b327769890361…

MALICIOUS

PDF

86.4 KB Created: 2021-07-05 07:56:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 640f6692d24b1188bd3330106d734001 SHA-1: 455861c4f23b896798ecf364480ce5b459870721 SHA-256: af5b3277698903612b6cdc3b54e037585028a2ef826dc1171674f743c1733eaf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external URIs and points to compromised WordPress upload storage, suggesting it's designed to redirect users to malicious sites. The document body is heavily obfuscated, but the presence of numerous URLs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://infrive.ru/uplcv?utm_term=shingles+in+young+adults
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/a0fee800efad9f0cd977ec1d04da6884/maguger.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/qhsc9e9v7h2v08mfivblc6opn6/lasuxiwizopabamotebuduko.pdf
    • http://vintageguitar.ru/ckfinder/userfiles/files/sumowewuxiwufazojumulugiw.pdf
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/aaced4e9dd99d92a1e27697682ab620b/78737820556.pdf
    • http://artpolinakuzina.ru/pict/file/fizabe.pdf
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/45aa8c59abaee2c214c34e8ff6c3aa46/dirusibib.pdf
    • https://mttrasportisrl.it/dati/upload/file/radegigek.pdf
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c23ac72fcc5---29167003034.pdf
    • http://greenworx.eu/images/uploads/files/39223042507.pdf
    • https://louvre.lv/res/wysiwyg/file/gawavubiligiwuxapif.pdf
    • http://faradbox.pl/files/file/raxudetu.pdf
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/k4omdal17ios253a45vbg9laip/80348946908.pdf
    • http://seyrimerdin.com/userfiles/file/63225268609.pdf
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/19ec9f3d7a479c99440062a848e6e671/64802406612.pdf
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1607474b694e4c---40663772107.pdf
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/f96fc3541225a5d64e6513ed44e05a8c/batoposiganilesidono.pdf
    • http://wadirumshootingstars.com/userfiles/file///79948248851.pdf
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/gtq9nh03r9i4b0oecqugd617im/5920894417.pdf
    • https://www.bakirkoytemsilcisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5b62aab78---zuxuj.pdf
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/950c1972b15a61db2cdadbf828bdf791/94082742028.pdf
    • http://assushop.com/userfiles/assushop.com/file/bupigi.pdf
    • https://travelsafeway.com/userfiles/file/89532580915.pdf
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/6a0ccc014415f230349f06fe23ecb1da/noxudojujibo.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_off0000efdd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFDD 16792 bytes
font_01_sfnt_off000107f4.bin
f1d8f17c99b9d8ead612f58d8cb24ca9542bf898d27319155670e8a72e4401d9
pdf-font-stream PDF embedded font (sfnt) at offset 0x107F4 10716 bytes
font_02_sfnt_off0001204d.bin
d6257014ff17bb1926bd5d06c996475b9a5ec98608be1050817146afc0ffee2f
pdf-font-stream PDF embedded font (sfnt) at offset 0x1204D 16868 bytes