Malicious PDF — malware analysis report

Static analysis result for SHA-256 855ad10c25e83f6c…

MALICIOUS

PDF

83.2 KB Created: 2021-08-20 03:55:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ecbe3444c04e27ec032e92ba527ccd8f SHA-1: 3dbada5249fbeeb640d7c2a936a72239d7152e99 SHA-256: 855ad10c25e83f6c7e6e5a914cc18eb73e475776d19158f757e065402e2d0f04
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://archism.ru/uplcv?utm_term=vanderbilt+adhd+parent+scale+scoring
    • https://textosolutionslinguistiques.ca/upload/editor/file/jozesaxebodazadunidupif.pdf
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/5d07d5434bb44b84c2c877f97b5d0484/fosasulafuta.pdf
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/44cd12c2e624a696fa829b0686e1029f/73548221451.pdf
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/jhd1bddfkmj10msma1v5famh6g/kotaduwikagesisawosikap.pdf
    • http://elitvorota.ru/f/file/48509822793.pdf
    • http://mhinflatable.com/upload/file/jazosekuwefamibiluwafejus.pdf
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/rilizutepofokobanatit.pdf
    • http://skrn.cz/pic/file/pekoru.pdf
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/u0jr8d304mtb9bb521mos3329f/zorukalodeno.pdf
    • http://steelbo.com/uploads/admins/u0/files/20210805105057.pdf
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/c176bd132923102bd2efe2ab80c02038/tumerelilozilo.pdf
    • http://uctodane.cz/UserFiles/File/kalitudokejozefa.pdf
    • https://camgloberealtor.com/userfiles/file/39089325292.pdf
    • https://wilocom.ro/ckfinder/userfiles/files/dononux.pdf
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c85ac4474b---merorijomij.pdf
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160aecf92adef3---67194929126.pdf
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/16093a10ad7cd0---xikanoziwaxaburarot.pdf
    • https://equinox-e.com/upload/UserFiles/file/95230001718.pdf
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/17ef9448ccb765647036fa825d3ae7ac/29974640597.pdf
    • https://bestcoloringpages.com/userfiles/file/87094365218.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/55e658a970f65c49f69a342e7e8b0deb/gesifofepafuwejowoguzaz.pdf
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/ajbbmjtnloaj7ggu0fbt19krt2/7036274732.pdf
    • http://screen.by/images/file/8461313742.pdf
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/464b661f30d57f9f91d850775ddaca33/24586420784.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_off0000e105.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE105 16792 bytes
font_01_sfnt_off0000f91c.bin
5b7da86dd92615063622d97b835e590023b44279dcc25b089349bf5a0e13cffe
pdf-font-stream PDF embedded font (sfnt) at offset 0xF91C 10904 bytes
font_02_sfnt_off000111ce.bin
feff1fc7c3c2f4bfb862c570d94391d4124f4c210fc78f06b3e1199e256bc5b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x111CE 16772 bytes