Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1841b38f190e6ca…

MALICIOUS

PDF

77.1 KB Created: 2021-07-01 17:12:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: de6842f8d48422aac001478ce5b9bce5 SHA-1: c5cf3bc2480e9767a0702b219451711c6394c200 SHA-256: a1841b38f190e6ca833b5a83fb25f0661da12aac2e6134fe4ccc118ef4cd959d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites, likely serving as a distribution point for phishing or malware. The presence of external URIs and link farm heuristics strongly suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://chcial.ru/uplcv?utm_term=physics+principles+with+applications+pdf+free
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a16858372e7---gonofalewaduxavakojebig.pdf
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608fad720f445---48902618718.pdf
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/b44777abfb40869acac9e4b95c3ae9b6/2341268917.pdf
    • https://canevastoilestjean.com/upload/editor/file/80609804680.pdf
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084e42156997---fajakebezilapugar.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a676feda32f---41752155369.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609682e72f242---88181431329.pdf
    • http://orderleesushi.com/uploads/files/minefu.pdf
    • https://bbpartner.cz/userfiles/file/94717123987.pdf
    • http://safarang.com/basefile/files/56481573655.pdf
    • http://creativeindustries.ru/uploads/userfiles/file/dupitezaf.pdf
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607cb2458ed6f---19822659997.pdf
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16072ef4dc8c59---91496033549.pdf
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160709cb672b66---niwisudo.pdf
    • https://akproauto.com/nbloom/fckuploads/file/32202149638.pdf
    • http://videofilm-tv.ru/content/File/gafutitozafixuj.pdf
    • http://travisreunion.com/clients/1/1d/1d9c560ef9ee6310b862f4c9d288d7bd/File/83963078594.pdf
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a79897ee768---87793253429.pdf
    • https://caribemed.com/userfiles/file/72863612179.pdf
    • https://ocw.tw/uploads/files/23873949394.pdf
    • http://music-summer-courses.eu/upload/files/bifibanirunam.pdf
    • http://hookmyweddingup.net/clients/73542/File/5025888224.pdf
    • https://thekolkatapackersmovers.com/ckfinder/userfiles/files/jagob.pdf
    • http://wsm.hk/images/files/borolekip.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b7ef50b58fc---20609965669.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_off0000cb9d.bin
0c58e1af426a7df43e02b663877c75d896d17444c85d409ab89a627d8687957e
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB9D 10916 bytes
font_01_sfnt_off0000e4ee.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4EE 16792 bytes
font_02_sfnt_off0000fd00.bin
db37f41574889a0318409b93261dc9ce47b6fe40216be9ec2b6c95720b9712b3
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD00 16156 bytes