Malicious PDF — malware analysis report

Static analysis result for SHA-256 845193a3d0cc89ca…

MALICIOUS

PDF

86.0 KB Created: 2021-06-14 15:24:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: efadc59b7fd8758502f69cc2c82bc1ea SHA-1: 99d6fe7f8cb8a6dbada17a33ebcf853903ac7ae0 SHA-256: 845193a3d0cc89ca791f9827202a6bba86071ba86e4c307e65c9f64e38ffb48f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document is detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous links to external sites, many hosted on compromised WordPress installations, suggesting a link farm designed to redirect users to malicious content. The document body, though truncated, contains keywords related to 'computer science pdf free download', indicating a lure to trick users into downloading a malicious file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://allytemp.ru/uplcv?utm_term=tps+computer+science+12th+pdf+free+download PDF link annotation
    • https://realestateconnect.pro/wp-content/plugins/super-forms/uploads/php/files/pjo0v7tqtpv0p7n4h3t8cljmu7/26748998177.pdfIn PDF document text
    • http://csc025.com/userfiles/file/20210608091857_0ffi19.pdfIn PDF document text
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/rtabfjd5odfqijstnbs2e7521b/45283893348.pdfIn PDF document text
    • http://archi1919.com/smlclub-files/file/57140101456.pdfIn PDF document text
    • http://kistours.hu/userfiles/file/90384707857.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607b19794e108---bavavusitiroxukurov.pdfIn PDF document text
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/onur3ridi8t6dge4702nkqnma4/39602534376.pdfIn PDF document text
    • http://parkhigh65.com/clients/4970/File/92615077913.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/42ef079f7b5505a5cb03653a135dfc29/23672255237.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/68973241705.pdfIn PDF document text
    • http://womensmentalhealthmd.com/clients/9/9a/9a9ccad1be43d50cbc9928f06550b956/File/nugudojajelevolevuma.pdfIn PDF document text
    • http://garantc.ru/userfiles/file/mojokivawukalekewoximi.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/ujc2mb9uck08l372mt3pbpqbhi/80340321686.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/4bk85fbfm4j9bipddto9j24be1/20498839777.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ff21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF21 6416 bytes
SHA-256: 15f1f49b80f446e7933a40d6c5645ba9b1ad3ddb6c90b7ed74ec66770e7def8a
font_01_sfnt_off00010eea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EEA 5620 bytes
SHA-256: 5868ff30ca0bac0ee13475d70aa83caa3a999ea91b867fab59d249ee7d003e9c
font_02_sfnt_off000121f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121F2 11416 bytes
SHA-256: c2c507d96485f1b591eceec47e7f7ae66de26b6af2b1835d72a1eefffafcbbfd