Malicious PDF — malware analysis report

Static analysis result for SHA-256 dcfdc0359da849b2…

MALICIOUS

PDF

70.9 KB Created: 2021-05-05 08:18:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: eb90cfecf1fb1b92b6802181d7bddb67 SHA-1: 684d8de0ea75f8f0662c08ceb77829d2bfc7042b SHA-256: dcfdc0359da849b280b242321b25e433577f9fd38fcb7a5d909445990031634c
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded links, many of which point to compromised WordPress upload directories, suggesting a phishing or redirection scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as phishing and a trojan. The document body, though obfuscated, contains text related to 'Bstc paper 2019 ki answer key', likely a lure to encourage users to click the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073076fede5d---vanaxakokonuxud.pdf
    • https://capitaleny.com/wp-content/plugins/super-forms/uploads/php/files/1354d0263326823572b2b5cb31911acb/78529414181.pdf
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16088c19c3f459---valiluderavokizajemoneb.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/3fdd1400518b0d186055ef9145a29168/wagexukuwajomipimu.pdf
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cff61e910d---dewupupimuxeni.pdf
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160864832aa9fc---48379376587.pdf
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/975d140f111799f59ed74d8f9bfc3815/66887198758.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fde23a98e1---59761940047.pdf
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/0a75203163a86c0343735989edce1abb/19796612787.pdf
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/pv8lefgbrqk2p2e3lkobss5h0d/89686805294.pdf
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/9c1d491ef46a22198f0fc08d706bb2a3/81493403842.pdf
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/d3e4215f77c5417aa185ab752e74e8ab/tulidusifotika.pdf
    • https://www.reflectionuk.com/wp-content/plugins/super-forms/uploads/php/files/uiqitn9dftnqp6a93hhvj1g424/kosubojaliza.pdf
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/4b8b606cd424b547c51198d3aced8a66/lotunuzitar.pdf
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf51a2e3f4---71596619728.pdf
    • https://takeorders.online/wp-content/plugins/super-forms/uploads/php/files/djpnvoikd69va0nl501vpv01fe/14492205121.pdf
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/0fqegejpi6fdkaarjlmp974sd9/kimukak.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=bstc+paper+2019+ki+answer+key
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc45.bin
9bdafde38eafba8356b3b85d132f79a75e8b600fa5c879f003b346dbd98e6610
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC45 5684 bytes
font_01_sfnt_off0000efc9.bin
1702d88cfb3879c6fc6eadbd5f9f6fed12b5a45703db77df6e37aa9c178c8720
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC9 10472 bytes