Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a392d87ca625267…

MALICIOUS

PDF

71.4 KB Created: 2021-07-06 16:42:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: e8909a9dba57656a14217af3799afdbb SHA-1: 3055b3d9ccb1eac104e25f0be75f279b08ce80d0 SHA-256: 1a392d87ca625267e07706422d0bed71dbd0af3fd8f3797dd63de8ec1ab51729
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous URLs pointing to compromised WordPress installations, suggesting it's used for phishing or distributing further malware. The PDF structure itself does not contain executable scripts, but the embedded URLs are the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://wastran.ru/uplcv?utm_term=write+a+note+on+history PDF link annotation
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/29a518331cf1b15a349b67ef1b14ff7a/41669821709.pdfIn PDF document text
    • http://olgapolyakova.com/files/files/65912886145.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/0b079c26c0bc82b14b25b1046160210c/limotap.pdfIn PDF document text
    • http://suamayin.biz/userfiles/file/xeginarezuf.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/3541af65317543311152e62045c54411/retez.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609f93b0c9b0b---xetixupa.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5d2d59bd16---55170441014.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bfa7d08c2a4---nesijefapamodutigexujute.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160ab22d467953---vibos.pdfIn PDF document text
    • http://eurolocal.info/sites/default/files/images/file/pevapizadef.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/st45ik8g78v8s4d1m1raeli63j/55329279963.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/0s3qrqh16ub2vus9r1hfk7a276/rawutivibejariko.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/45bfc1fa6126315a6c28476cb5f04c76/62185325745.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/c4580a5f809257ddb24d9bf28e92a5ac/71435294171.pdfIn PDF document text
    • http://dom-2000.ru/ckfinder/userfiles/files/68017122928.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160787dc7d1505---genigimululorujij.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/kj60kufclvja44si0nop2dvcpo/nolakovebew.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/30976d744c98ff3423efe439021b3112/34857551283.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c867c102578---zuzamimipubenujitasur.pdfIn PDF document text
    • http://bluekeydigital.com/images/pic/file/68891699404.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/9661143349.pdfIn PDF document text
    • http://orkoien.com/userfiles/files/wilufemuki.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9161a0f95---xovuvododobenerijolop.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160947b8d3e6de---59436519308.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/e1637142a36f02322c8f61408502ad6c/55016886171.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_off0000ba77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA77 10264 bytes
SHA-256: f9c5fb63f9eb61f1e12c44e0f97e53472e171ecd20af41a628bbcd1354024ece
font_01_sfnt_off0000d18a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD18A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e99c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE99C 15204 bytes
SHA-256: 477f7f65623889dc5264e2eeb9c90b6df6f8f05187b4dbd3b220f71b566ec370