Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5acc81b0b0ef5e0…

MALICIOUS

PDF

77.6 KB Created: 2021-09-01 03:35:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 19355ed74ee8211793bc2879bd2ef5ed SHA-1: 77170ca318721bbf089eeccd2a12604ac0b30a83 SHA-256: a5acc81b0b0ef5e0dda25cda661ee67388495b48f63b8c093ebba8c27d21434f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to numerous compromised websites, many of which are WordPress installations hosting further PDF files. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to download further malicious content or exploit vulnerabilities. The document body is unreadable, but the heuristic firings and URL analysis confirm a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9829

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 https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/c4873296faf14b9ff2f9a8e4cb66a312/jasikekisowazufata.pdf In PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c08cef8ed90---jojokeradubomomalozujeti.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/cb9212050de8401f25383763c10b709c/lipumibakunoberivedibe.pdfIn PDF document text
    • https://studiorampinelli.com/file/62134403753.pdfIn PDF document text
    • https://art4you.sk/editor_uploads/system/files/59737799074.pdfIn PDF document text
    • http://danieldesignpro.com/userfiles/44303682434.pdfIn PDF document text
    • https://campermagazine.tv/public/file/520222906.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd6ecaac3f---jaworoziwoxed.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16108224c67ebe---96045896139.pdfIn PDF document text
    • https://pointsourcegroup.com/wp-content/plugins/super-forms/uploads/php/files/7043f9c58da5d2ff6f00600af4c3247e/14780307642.pdfIn PDF document text
    • http://bjbtrh.com/files/pic/file/29489541423.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608b783fbf44f---duwesanobagenipigoz.pdfIn PDF document text
    • http://newo.ru/files/files/woxofidorakuv.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c2075732fa8---buwokobenenamafobusizi.pdfIn PDF document text
    • http://onsijsselstein.nl/userfiles/files/luxiruwiv.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/f7pb90g86gddiel34u53hifk0f/2078878440.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608c357134859---9342956229.pdfIn PDF document text
    • http://elskenecologie.nl/files/pufurepubegagow.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/9v0apvbmnkem1cit5mv76s85k4/refaz.pdfIn PDF document text
    • https://pelicanfinancialnetwork.com/ckfinder/userfiles/files/16332465880.pdfIn PDF document text
    • http://policylic.com/uploads/files/55114477575.pdfIn PDF document text
    • http://nfc.soo.jp/file/75030075633.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ab8df76a2ec---9542221936.pdfIn PDF document text
    • http://rcot.by/pics/files/79750494743.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160f1a9b8a675c---zajivetelitokuvused.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/42h2a9mpbcpfjcjohrd8po1bea/tepesumu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=our+father+chords+and+lyricsPDF 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_off0000c7fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e011.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE011 10812 bytes
SHA-256: a6ae0d82c237fbdb14798a53384855f1cd08ee8d8f0db3811533ff0aff5ff022
font_02_sfnt_off0000f8fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8FC 18608 bytes
SHA-256: 7fda2a3511bdc5c39577453883d120caa73d879b5dca4c118d97c5b2b8e69e4f