Malicious PDF — malware analysis report

Static analysis result for SHA-256 a131e1e9e6da95e8…

MALICIOUS

PDF

81.4 KB Created: 2021-09-16 03:00:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: dc6b69639bba197548657be1f75e9ff1 SHA-1: 6d1c12d4c0bc5dd99a9bfba055f5c2ac74dab6da SHA-256: a131e1e9e6da95e813eb1f90ebad7765def6251c07adba306cedb5a15e1f2b17
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of external URI links and link farms on disposable hosting further supports a phishing lure, likely related to search terms like 'connect laptop to phone screen'. No scripts were extracted, but the PDF structure itself is weaponized.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://smidgel.ru/uplcv?utm_term=connect+laptop+to+phone+screen PDF link annotation
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/01748fbd1d3533b7b7982c2093db7d9c/xipud.pdfIn PDF document text
    • http://sahcarpets.com/userfiles/file/28881786986.pdfIn PDF document text
    • http://solemarservizi.it/userfiles/files/10226537135.pdfIn PDF document text
    • https://tmtteks.com/files/31756922945.pdfIn PDF document text
    • https://mondoaudio.it/img/uploaded/file/69763146120.pdfIn PDF document text
    • https://snqrsl.quebec/upload/editor/file/kifarofusetunil.pdfIn PDF document text
    • http://unicorn-furnitures.com/d/files/sifatirifixesegowivoro.pdfIn PDF document text
    • http://cgl.lu/userfiles/files/51474383402.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/6fb254239e2342f49cf173d6fb080522/witet.pdfIn PDF document text
    • http://bitree.net/ckfinder/userfiles/files/49932072198.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/161409075b84ac---puvabisuxiwagan.pdfIn PDF document text
    • https://infypos.com/infyposcms/media/19790077661.pdfIn PDF document text
    • https://www.sherpachristain.org.np/ckfinder/userfiles/files/belidikoremuga.pdfIn PDF document text
    • http://kleinschadenexpert.com/userfiles/file/jasevumawipubodob.pdfIn PDF document text
    • http://avtosfera28.ru/userfiles/file/34302495875.pdfIn PDF document text
    • http://recrute.fr/files/files/besolumivuzoxuvogenu.pdfIn PDF document text
    • https://kungfuclasshongkong.com/louis/taichi/ckfinder/userfiles/files/1448074860.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/25e1bdd40007f21fc43be54a9944f879/kogerugozasurubizole.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/3fv29bc3f2peic3es2tncvcg55/25328886096.pdfIn PDF document text
    • http://photopuzzle.net/userData/board/file/bisujum.pdfIn PDF document text
    • http://shippingengineering.com/files/ckeditorothers/jitakupavulopemudaxevo.pdfIn 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
    • 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_off0000dbc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC8 17200 bytes
SHA-256: b685b2970ed62f5f027139193e32b00fec595941d11cd4f79d7e375ad9fa2c0c
font_01_sfnt_off0001085f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1085F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012076.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12076 10412 bytes
SHA-256: 5f9d1b7b80d1e058b6370232051f21373bedabac13c5769c4e3b2dff3105d445